Abstract

In this study, the p-type Ga-doped Cu₃Sb_1−xGa_xSe₄ compounds were fabricated by melting, annealing, grinding, and spark plasma sintering (SPS). The transport properties of Ga-doped Cu₃Sb_1−xGa_xSe₄ compounds were investigated. As Ga content increased, the hole concentration of Cu₃Sb_1−xGa_xSe₄ compounds increased, which led to an increase in electrical conductivity. Meanwhile, the Seebeck coefficient of the Cu₃Sb_1−xGa_xSe₄ compounds decreased as Ga content increased. The extra phonon scattering originating from Ga-doping effectively depressed the lattice thermal conductivity of the Cu₃Sb_1−xGa_xSe₄ compounds. The ZT value of Cu₃SbSe₄ markedly improved, which is primarily ascribed to the depressed lattice thermal conductivity and the increased electrical conductivity. The highest ZT value for the Cu₃Sb_0.985Ga_0.015Se₄ compound was 0.54 at 650 K, which is two times higher than that of a pure Cu₃SbSe₄ compound. View Full-Text