应变β-Cu2Se的热电性能,ACS Applied Materials & Interfaces

当前位置： X-MOL 学术 › ACS Appl. Mater. Interfaces › 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.)

应变β-Cu2Se的热电性能
ACS Applied Materials & Interfaces ( IF 8.3 ) Pub Date : 2021-07-20 , DOI: 10.1021/acsami.1c08686
Wei Cao _{1,

2} , Ziyu Wang _{2,

3} , Ling Miao ₄ , Jing Shi ₁ , Rui Xiong ₁

Affiliation

近年来，Cu ₂ Se的高温相，即β-Cu ₂ Se，由于其优异的热电效率而受到越来越多的关注。β-Cu ₂ Se 中的 Cu 离子在Se 离子晶格的框架之间显示出明显的离子-液体行为。许多实验操作可能会导致晶格结构的差异。实验合成的 β-Cu ₂ Se 是 p 型，热电器件需要具有接近品质因数的 p 型和 n 型材料。研究应变的影响和 n 型 β-Cu ₂ Se的可能性是必不可少的。利用第一性原理计算和分子动力学模拟，我们研究了应变 β-Cu ₂的热电性能硒。结果表明，n 型 β-Cu ₂ Se 可以像 p 型一样表现出优异的zT值。施加压应变是提高功率因数的有效方法。拉伸应变将导致低晶格热导率，从而提高 p 型zT值。在 800 K 时，n 型和 p 型 β-Cu ₂ Se的预测最大zT值可以分别达到 1.65 和 1.71。考虑到在实验中施加应变具有挑战性，我们提出了一种操纵晶格结构和载流子类型的可行策略：掺杂卤素元素。我们的结果为基于Cu ₂ Se 的热电器件提供了指导。

"点击查看英文标题和摘要"

Thermoelectric Properties of Strained β-Cu2Se

In recent years, the high-temperature phase of Cu₂Se, namely, β-Cu₂Se, has attracted increasing attention due to its outstanding thermoelectric efficiency. The Cu ions in β-Cu₂Se show a distinct ion–liquid behavior between the framework of a Se ion lattice. Many experimental operations may lead to a discrepancy in the lattice structure. Experimentally synthesized β-Cu₂Se was p-type, and a thermoelectric device needs both p-type and n-type materials with a close figure of merit. Studying the effect of strain and the possibility of n-type β-Cu₂Se is essential. Utilizing first-principles calculations and molecular dynamics simulations, we investigate the thermoelectric performance of strained β-Cu₂Se. The results show that the n-type β-Cu₂Se can exhibit superior zT values like the p-type one. Applying compressive strain is an effective way to promote the power factor. The tensile strain will lead to a low lattice thermal conductivity and thus boost the p-type zT values. The predicted maximum zT values for n-type and p-type β-Cu₂Se can reach 1.65 and 1.71 at 800 K, respectively. Considering the fact that applying strain is challenging in experiments, we propose a feasible strategy to manipulate the lattice structure and carrier type: doping halogen elements. Our results provide a guide for Cu₂Se-based thermoelectric devices.

更新日期：2021-07-28

点击分享查看原文

点击收藏

阅读更多本刊新发论文本刊介绍/投稿指南