当前位置: X-MOL 学术Adv. Mater. › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
High Thermoelectric Performance in Phonon-Glass Electron-Crystal Like AgSbTe2
Advanced Materials ( IF 27.4 ) Pub Date : 2023-11-27 , DOI: 10.1002/adma.202307058
Vaishali Taneja 1 , Subarna Das 1 , Kapildeb Dolui 2 , Tanmoy Ghosh 1 , Animesh Bhui 1 , Usha Bhat 3 , Dinesh Kumar Kedia 4 , Koushik Pal 5 , Ranjan Datta 3 , Kanishka Biswas 1
Affiliation  

Achieving glass-like ultra-low thermal conductivity in crystalline solids with high electrical conductivity, a crucial requirement for high-performance thermoelectrics , continues to be a formidable challenge. A careful balance between electrical and thermal transport is essential for optimizing the thermoelectric performance. Despite this inherent trade-off, the experimental realization of an ideal thermoelectric material with a phonon-glass electron-crystal (PGEC) nature has rarely been achieved. Here, PGEC-like AgSbTe2 is demonstrated by tuning the atomic disorder upon Yb doping, which results in an outstanding thermoelectric performance with figure of merit, zT ≈ 2.4 at 573 K. Yb-doping-induced enhanced atomic ordering decreases the overlap between the hole and phonon mean free paths and consequently leads to a PGEC-like transport behavior in AgSbTe2. A twofold increase in electrical mobility is observed while keeping the position of the Fermi level (EF) nearly unchanged and corroborates the enhanced crystalline nature of the AgSbTe2 lattice upon Yb doping for electrical transport. The cation-ordered domains, lead to the formation of nanoscale superstructures (≈2 to 4 nm) that strongly scatter heat-carrying phonons, resulting in a temperature-independent glass-like thermal conductivity. The strategy paves the way for realizing high thermoelectric performance in various disordered crystals by making them amorphous to phonons while favoring crystal-like electrical transport.

中文翻译:


AgSbTe2 等声子玻璃电子晶体的高热电性能



在具有高电导率的结晶固体中实现类玻璃的超低导热率,这是高性能热电材料的关键要求,仍然是一个艰巨的挑战。电和热传输之间的仔细平衡对于优化热电性能至关重要。尽管存在这种固有的权衡,但具有声子玻璃电子晶体(PGEC)性质的理想热电材料的实验实现却很少实现。在这里,通过调整 Yb 掺杂上的原子无序度来证明类似 PGEC 的 AgSbTe 2 ,这导致了出色的热电性能,在 573 K 时的品质因数zT ≈ 2.4。Yb 掺杂引起的增强的原子排序减少了原子有序度之间的重叠。空穴和声子平均自由程,从而导致 AgSbTe 2中类似 PGEC 的输运行为。在保持费米能级 ( E F ) 位置几乎不变的情况下,观察到电迁移率增加了一倍,这证实了 AgSbTe 2晶格在 Yb 掺杂用于电传输时增强的结晶性质。阳离子有序域导致形成纳米级超结构(约 2 至 4 nm),强烈散射载热声子,从而产生与温度无关的玻璃状导热性。该策略通过使各种无序晶体成为非晶态为声子,同时有利于类晶体的电传输,为在各种无序晶体中实现高热电性能铺平了道路。
更新日期:2023-11-27
down
wechat
bug