N-type Se&Lu-codoped Bi₂Te₃ nanopowders were prepared by hydrothermal method and sintered by spark plasma sintering technology to form dense samples. By further doping Se element into Lu-doped Bi₂Te₃ samples, the thickness of the nanosheets has the tendency to become thinner. The electrical conductivity of Lu_0.1Bi_1.9Te_3-xSe_x material is reduced with the increasing Se content due to the reduced carrier concentration, while the Seeback coefficient values are enhanced. The lattice thermal conductivity of the Lu_0.1Bi_1.9Te_3-xSe_x is greatly reduced due to the introduced point defects and atomic mass fluctuation. Finally, the Lu_0.1Bi_1.9Te_2.7Se_0.3 sample obtained a maximum ZT value of 0.85 at 420 K. This study provides a low-cost and simple low-temperature method to mass production of Se&Lu-codoped Bi₂Te₃ with high thermoelectric performance for practical applications.

A broad tunability of the thermoelectric and mechanical properties of CoSb₃ has been demonstrated by adjusting the composition with the addition of an increasing number of elements. However, such a strategy may negatively impact processing repeatability and composition control. In this work, single-element-filled skutterudite is engineered to have high thermoelectric and mechanical performances. Increased Yb filling fraction is found to increase phonon scattering, whereas cryogenic grinding contributes additional microstructural scattering. A peak zT of 1.55 and an average zT of about 1.09, which is comparable to the reported results of multiple-filled SKDs, are realized by the combination of simple composition and microstructure engineering. Furthermore, the mechanical properties of Yb single-filled CoSb₃ skutterudite are improved by manipulation of the microstructure through cryogenic grinding. These findings highlight the realistic prospect of producing high-performance thermoelectric materials with reduced compositional complexity.