Realizing ultralow thermal conductivity in Cu3SbSe4 via all-scale phonon scattering by co-constructing multiscale heterostructure and IIIB element doping

This article attempts to realize ultralow lattice thermal conductivity in Cu 3 SbSe 4 by substitution Sb site by IIIB elements (Sc/Y), the facial microwave reaction were chosen to fabricate the above samples. The results show that group IIIB elements combined with multiscale heterostructure can effectively suppress the lattice thermal conductivity in Cu 3 SbSe 4 system, resulting in a typical low value of 0.491 W/m/K and 0.481 W/m/K in Cu 3 Sb 0.92 Sc 0.08 Se 4 and Cu 3 Sb 0.92 Y 0.08 Se 4 at 623 K, respectively. Eventually, a peaking zT value of 0.47 and 0.46 can be obtained for each doping sample. This research highlights a novel strategy by co-constructing multiscale heterostructure and IIIB elements doping for realizing multiscale phonon scattering in Cu 3 SbSe 4 materials.