Enhancement of Thermoelectric Performance in CuSbSe₂ Nanoplate‐Based Pellets by Texture Engineering and Carrier Concentration Optimization

Abstract This work reports the thermoelectric properties of the CuSbSe₂‐x mol% PtTe₂ (x = 0, 0.5, 1.0, 1.5, and 2.0) pellets composed of highly oriented single crystalline nanoplates. CuSbSe₂‐PtTe₂ single crystalline nanoplates are prepared by a wet‐chemical process, and the pellets are prepared through a bottom‐up self‐assembly of the CuSbSe₂‐PtTe₂ nanoplates and spark plasma sintering (SPS) process. X‐ray diffraction and field emission scanning electron microscopic analyses show a highly textured nature with an orientation factor of ≈0.8 for (00l) facets along the primary surface of the pellets (in‐plane, perpendicular to the SPS pressure). By this way, bulk‐single‐crystal‐like electrical and thermal transport properties with a strong anisotropy are obtained, which results in an effective optimization on thermoelectric performance. The maximum in‐plane thermoelectric figure‐of‐merit ZT value reaches 0.50 at 673 K for CuSbSe₂‐2.0 mol% PtTe₂ pellet, which is about five times higher than the in‐plane ZT (0.10) for pure CuSbSe₂.