Sihi Antik, Pandey Sudhir K
School of Basic Sciences, Indian Institute of Technology Mandi, Kamand-175075, India.
School of Engineering, Indian Institute of Technology Mandi, Kamand-175075, India.
J Phys Condens Matter. 2021 May 7;33(22). doi: 10.1088/1361-648X/abeca8.
Recently, SnTe has gained attention due to its non-trivial topological nature and eco-friendly thermoelectric applications. We report a detailed temperature dependent electronic structure of this compound using DFT andmethods. The calculated values of bandgaps by using PBEsol andmethods are found to be in good agreement with the experiment, whereas mBJ underestimates the bandgap. The averaged value of diagonal matrix elements of fully screened Coulomb interaction (W̄) at= 0 eV for Sn (Te) 5orbitals is ∼1.39 (∼1.70) eV. The nature of frequency dependentW̄(ω)reveals that the correlation strength of this compound is relatively weaker and hence the excited electronic state can be properly studied by full-many-body technique. The plasmon excitation is found to be important in understanding this frequency dependentW̄(ω). The temperature dependent electron-electron interactions (EEI) reduces the bandgaps with increasing temperature. The value of bandgap at 300 K is obtained to be ∼161 meV. The temperature dependent lifetimes of electronic state along--Γ direction are also estimated. This work suggests that EEI is important to explain the high temperature transport behaviour of SnTe.
最近，SnTe因其非平凡的拓扑性质和环保的热电应用而受到关注。我们使用密度泛函理论（DFT）方法报告了该化合物详细的温度相关电子结构。使用PBEsol方法计算的带隙值与实验结果吻合良好，而mBJ方法则低估了带隙。对于Sn（Te）5轨道，在能量为0电子伏特时，完全屏蔽库仑相互作用（W̄）的对角矩阵元平均值约为1.39（约1.70）电子伏特。频率相关的W̄（ω）的性质表明该化合物的相关强度相对较弱，因此可以通过全多体技术适当地研究激发电子态。发现等离子体激元激发对于理解这种频率相关的W̄（ω）很重要。温度相关的电子-电子相互作用（EEI）随着温度升高而减小带隙。在300 K时带隙值约为161毫电子伏特。还估计了沿-Γ方向电子态的温度相关寿命。这项工作表明，EEI对于解释SnTe的高温输运行为很重要。
