In recent years, skutterudite filled
with electronegative elements
(S, Se, Cl, Br) has attracted the extensive attention of researchers.
By doping electron donors (Pb, Ni, or Te, S, Se) at the Co or Sb sites,
the electronegative elements can form thermodynamically stable compounds
in the intrinsic pores of the skutterudite, substantially expanding
the research scope of skutterudite. In this study, S0.05Co4Sb11.3Te0.6Se0.1 skutterudite
was synthesized at high pressure and high temperature, with a pressure
range of 2.0–3.5 GPa. The phase composition, micro-morphology,
and electrical and thermal transport properties were systematically
characterized. The micromorphology analysis shows that the introduction
of S element and substituting Te and Se at the Sb sites inhibit the
grain growth in a suitable high-pressure environment. Substantial
differences are observed in the directions of the lattice stripes
in the samples, and rich grain boundaries and many lattice distortions
and dislocation defects occur. The carrier concentration can be optimized
by filling the voids of the skutterudite with a few S atoms, and the
thermoelectric properties can be optimized by scattering phonons through
resonance scattering and defect scattering. The samples synthesized
at a pressure of 3.0 GPa and a temperature of 900 K have a maximum
power factor of 23.85 × 10–4 W m–1 K–2 and a maximum zT value of
1.30 at a test temperature of 773 K.