We introduce Sb₂Si₂Te₆ as a high-performance thermoelectric material. Single-crystal X-ray diffraction analysis indicates that Sb₂Si₂Te₆ has a layered two-dimensional structure with Sb³⁺ cations and [Si₂Te₆]⁶⁻ units as building blocks adopting the Fe₂P₂Se₆ structure type. Sb₂Si₂Te₆ is a direct-band-gap semiconductor with valence-band maximum and conduction-band minimum at the Z point in the Brillouin zone, where the band is doubly degenerate. Polycrystalline bulk pellets of Sb₂Si₂Te₆ with randomly packed grains exhibit an intrinsically high thermoelectric figure of merit ZT of ∼1.08 at 823 K. We then create a cellular nanostructure with ultrathin Si₂Te₃ nanosheets covering the Sb₂Si₂Te₆ grains, which act as a hole-transmitting electron-blocking filter and at the same time cause extra phonon scattering. This dual function of the cellular nanostructure achieves an ultralow thermal conductivity value of ∼0.29 Wm⁻¹K⁻¹ and a high ZT value of ∼1.65 at 823 K for Sb₂Si₂Te₆, along with a high average ZT value of ∼0.98.

我们介绍Sb ₂ Si ₂ Te ₆作为高性能热电材料。单晶X射线衍射分析表明，Sb ₂ Si ₂ Te ₆具有层状二维结构，其中Sb ³⁺阳离子和[Si ₂ Te ₆ ] ⁶⁻单元作为采用Fe ₂ P ₂ Se ₆结构的结构单元类型。Sb ₂ Si ₂ Te ₆是一种带隙最大的导带隙半导体，在布里渊区的Z点处价带最大，导带最小值，在该带处双简并。具有随机堆积晶粒的Sb ₂ Si ₂ Te _6的多晶散装粒料在823 K时具有约1.08的固有高热电品质因数ZT。我们然后用覆盖Sb ₂ Si ₂ Te的超薄Si ₂ Te ₃纳米片创建了细胞纳米结构。₆用作空穴传输电子阻挡滤光片的晶粒同时会引起额外的声子散射。细胞纳米结构的双重功能实现了Sb ₂ Si ₂ Te ₆的超低导热系数值为〜0.29 Wm ^-1 K ^-1和823 K时的ZT值为1.65 ，以及平均ZT值为〜1.65。0.98。