Antimony telluride (Sb₂Te₃) has a very low $\mathit{ZT}$ value at room temperature, even though the alloys of Bi₂Te₃ and Sb₂Te₃ are the most widely used thermoelectric materials. Taking advantage of nano-structures and topological insulators (TIs), we report that high $\mathit{ZT}$ values of larger than 2 can be achieved in one quintuple-layer (QL, $\mathit{ZT}$ $\ge$ 2.1) and 4 QLs ($\mathit{ZT}$ $\ge$ 2.2) of Sb₂Te₃ at room temperature, while the $\mathit{ZT}$ value for bulk is around 0.5. For 1 QL, Seebeck coefficient has been greatly enhanced due to the increase in the number of band extrema by virtue of the twelvefold valley degeneracy from surface states. For 4 QLs, the high $\mathit{ZT}$ value is attributed to the much longer surface relaxation time associated with the robust nature of the topological surface states. Moreover, the $\mathit{ZT}$ values and the TI character of few-quintuple Sb₂Te₃ nanofilms demonstrate thickness(layer)-dependent behaviors. Our results offer significant clues for future applications and investigations of Sb₂Te₃-related quintuple layers as promising p-type thermoelectric materials and quasi-2D topological insulators for nanoelectronics.

碲化锑（Sb ₂ Te ₃）的含量很低$\mathit{ZT}$尽管Bi ₂ Te ₃和Sb ₂ Te ₃的合金是最广泛使用的热电材料，但在室温下仍能达到理想的热值。我们利用纳米结构和拓扑绝缘体（TI）的优势$\mathit{ZT}$ 一个五层（QL， $\mathit{ZT}$ $\ge$ 2.1）和4个QL（$\mathit{ZT}$ $\ge$2.2）Sb ₂ Te ₃在室温下，而$\mathit{ZT}$散装价值约为0.5。对于1 QL，由于表面状态的十二倍谷值简并，带极值的数量增加，因此塞贝克系数得到了极大的提高。对于4个QL，最高$\mathit{ZT}$该值归因于与拓扑表面状态的鲁棒性相关的更长的表面弛豫时间。而且，$\mathit{ZT}$几倍于Sb ₂ Te _3的纳米薄膜的热值和TI特性证明了厚度（层）依赖性行为。我们的结果为未来的应用和与Sb ₂ Te ₃相关的五元层层的研究提供了重要线索，这些五层层层是有前途的p型热电材料和准2D拓扑绝缘体，用于纳米电子学。