Understanding the Band Engineering in Mg2Si‐Based Systems from Wannier‐Orbital Analysis,Annalen Der Physik

当前位置： X-MOL 学术 › Ann. Phys. (Berlin) › 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.)

Understanding the Band Engineering in Mg2Si‐Based Systems from Wannier‐Orbital Analysis
Annalen Der Physik ( IF 2.2 ) Pub Date : 2020-05-07 , DOI: 10.1002/andp.201900543
Xiaojian Tan _{1,

2} , Yinong Yin ₁ , Haoyang Hu ₁ , Yukun Xiao ₁ , Zhe Guo _{1,

2} , Qiang Zhang _{1,

2} , Hongxiang Wang _{1,

2} , Guo‐Qiang Liu _{1,

2} , Jun Jiang _{1,

2}

Affiliation

The Mg₂Si

_{1 - x}

Sn_x solid solution is one of the most representative examples of band engineering, in which the thermoelectric performance is significantly improved by the conduction band convergence. The mechanism behind it is simply explained by the chemical differences between Si and Sn. Here a systematically theoretical study is reported based on Wannier function analysis. It is revealed that the band convergence in Mg₂Si

_{1 - x}

Sn_x is actually driven by the variation of lattice constant, since the heavy and light conduction valleys have different dependence on the bonding length. Alternatively, the band engineering can also be achieved by introducing cation dopants to tune the relative strength of the two chemical bonds directly. In Mg

_{2 - x}

Sr_xSi, a similar band convergence to Mg₂Si

_{1 - x}

Sn_x is predicted by the band structure calculations. This work provides an insightful understanding of the band convergence in Mg₂Si‐based materials, and it enables a more efficient and plentiful design for experimental studies.

中文翻译：