Influence of SnSe on thermoelectric properties of TiS₂-xSnSe composites via liquid-assisted shear exfoliation

In this study, the thermoelectric properties of TiS₂-xmol%SnSe (x = 0, 0.5, 1 and 2) composites prepared with liquid-assisted shear exfoliation (LASE) process were investigated. Results show that the carrier mobility of composites can be improved owing to the enhanced texturing degree via LASE process, and the carrier concentration can be increased together with SnSe addition due to charge transfer. Therefore, high power factors optimally to ~16.4 μW cm⁻¹ K⁻² can be obtained, which is almost 67% and 40% higher than that of the pristine and the LASE TiS₂, respectively. Unexpectedly, lattice thermal conductivity was increased probably due to the enhanced heterophase electrostatic force between TiS₂ and SnSe phase induced by charge transfer. As a result of compromise, a modest ZT maximum of ~0.48 at 673 K was obtained for TiS₂-1 mol%SnSe.