Pribramite CuSbSe2: Solid-State Synthesis and Thermoelectric Properties

Pribramite (CuSbSe₂) is gaining attention as a potential thermoelectric material due to its high thermopower and low thermal conductivity, although it remains relatively underexplored compared to more widely studied thermoelectric compounds. This study focused on optimizing the synthesis and sintering processes of CuSbSe₂ using mechanical alloying (MA) and hot pressing (HP) methods to enhance its thermoelectric performance. The desired pribramite phase was successfully synthesized in both mechanically alloyed powders and hot-pressed specimens, though secondary phases such as bytizite (Cu₃SbSe₃) and permingeatite (Cu₃SbSe₄) were identified. Thermogravimetric and differential scanning calorimetry analyses indicated a melting point for CuSbSe₂ between 723 and 728 K. Densely sintered samples achieved high relative densities of 98.6–99.4% through the MA–HP process. Electrical characterization revealed non-degenerate semiconductor behavior with temperature-dependent conductivity. Seebeck coefficient measurements confirmed p-type semiconductor characteristics, with holes as the major charge carriers. An intrinsic transition in the Seebeck coefficient was observed, with the transition temperature decreasing as the HP temperature increased. A maximum power factor of 0.23 mWm⁻¹ K⁻² was achieved at 623 K, while thermal conductivity steadily decreased across the measured temperature range of 323 K to 623 K. The highest dimensionless figure of merit (ZT) reached 0.28 at 623 K, indicating promising thermoelectric potential for CuSbSe₂.

Graphical Abstract