Triple-Conduction-Band Activation Enables High Out-of-Plane Thermoelectric Efficiency in n-type SnS Crystals

作者：Yixuan Hu, Shulin Bai, Dezheng Gao, Lizhong Su, Haonan Shi, Tian Gao, Shaoping Zhan, Shan Liu, Shibo Liu, Yichen Li, Pengpeng Chen, Rong Liu, Bingchao Qin, Li‐Dong Zhao · 发表于：Journal of the American Chemical Society · 年份：2025 · DOI：10.1021/jacs.5c18076 · 被引用次数：13 · 研究领域：Advanced Thermoelectric Materials and Devices、2D Materials and Applications、Topological Materials and Phenomena

The increasing interest for high-performance and earth-abundant thermoelectrics has motivated attention toward sulfide-based compounds. Among them, tin sulfide (SnS) has emerged as a promising candidate, especially in its p-type form. However, progress in n-type SnS has been hindered by poor electrical transport. In this study, Se and Pb are dual-alloyed into n-type Pnma -phase SnS crystals to achieve a considerable boost in carrier concentration, and the resultant triple-conduction-band activation significantly decouples carrier mobility and effective mass, facilitating a substantial enhancement in the out-of-plane three-dimensional (3D) charge transport. Meanwhile, the 2D phonon transport is further strengthened by the reduced group velocities and low-lying optical phonon modes, significantly suppressing the lattice thermal conductivity. Consequently, an exceptional out-of-plane ZT exceeding 2.0 at 698 K and an average ZT higher than 1.1 at 300–723 K are achieved in n-type Sn 0.63 Pb 0.37 S 0.55 Se 0.45 crystals within the Pnma- phase region. Furthermore, the as-fabricated single-leg thermoelectric device demonstrates a power generation efficiency of ∼8.3% under a temperature difference (Δ T ) of 472 K, showing promise for n-type thermoelectric sulfides. This work marks a significant advancement in the earth-abundant n-type SnS thermoelectrics through triple-conduction-band engineering, promoting the construction and potential application of all SnS-based devices.