单层TiSe2的结构,电子和热电特性
Uttam Paliwal1, Pradeep Tanwar2, K B Joshi3
1Department of Physics, Jai Narain Vyas University, Jodhpur, 342011, India. uttamphy@gmail.com.
Journal of molecular modeling
|February 22, 2024
概括
第一个原则计算显示单层TiSe2是金属和稳定的. 拉力应变会诱导半导体带隙,改变电子特性并提高热电性能,符合实验数据.
科学领域:
- 凝聚物质物理学 凝聚物质物理学
- 材料科学 材料科学 材料科学
- 计算材料科学科学 计算材料科学
背景情况:
- 单层过渡金属二甲基化物 (TMD) 对先进的电子和热电应用具有前景.
- 脱化物 (TiSe2) 是一种具有独特电子性能的分层材料,可以通过应变调整.
研究的目的:
- 通过第一原则计算,研究单层TiSe2的结构,电子和热电性能.
- 探索拉力应变对单层TiSe2.2电子带结构和热电性能的影响.
主要方法:
- 密度函数理论 (DFT) 计算使用PBE-GGA函数和平面波伪潜力方法 (量子ESPRESSO).
- 频段结构和状态密度计算以确定电子性质和稳定性.
- 博尔兹曼运输方程 (Boltztrap2) 与带结构相结合,用于热电性质计算.
主要成果:
- 单层TiSe2的优化格子参数与实验值有很好的一致性.
- 单层TiSe2具有金属性质,在M点的带重叠为0.44 eV.
- 拉伸应变通过打开带隙将TiSe2转化为半导体,带有应变依赖的电荷转移和带边移动.
- 计算的热电系数 (Seebeck系数,功率系数,功率图) 与实验数据保持一致,并显示温度依赖.
结论:
- 单层TiSe2具有机械稳定性,并具有固有的金属特性.
- 应用拉伸应变是一种有效的调整电子结构的方法,诱导半导体相,并可能增强热电特性.
- 计算结果为基于TiSe2的热电器件的设计和应用提供了宝贵的见解.
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