摘要
本文采用玻尓兹曼输运方程与密度泛函计算相结合的方法,理论研究了薄膜厚度对二维TiS2原子薄膜热电性能的影响。随着厚度的减小,薄膜的能带变平,电子有效质量增大而群速度减小,这造成了塞贝克系数的增大和电导率的减小。而且,薄膜的功率因子及最优载流子浓度也随厚度的减小而减小。我们讨论了薄膜功率因子减小的物理机制,并与其他二维体系的实验结果进行了比较分析。
With the discovery of graphene, two dimensional nanosheets are of great interest due to their novel physics. Among these 2D systems, transition metal sulficid nanosheets with strong correlated nature and ample compositional variations attract more and more attention. Here, by using density functional theory calculations and semi-classic Boltzmann transport equations, we investigated the influence of layer thickness on thermoelectric properties of TiS2 nanosheets, whose courtpart bulk material already shows some promising thermoelectric performance. Our theoretical results show that when the thickness is greater than the critical thickness for electronic quantum confinement and also is smaller than the critical thickness for phonon confinement, the TiS2 nanosheets will have better thermoelectric performance than its counterpart bulk. These finding is helpful for design novel high performance thermoelectric materials.
出处
《无机化学学报》
SCIE
CAS
CSCD
北大核心
2014年第3期506-510,共5页
Chinese Journal of Inorganic Chemistry
基金
国家自然科学基金(No.11104220)
陕西省自然科学基础研究计划(No.2011JQ1012)
陕西省教育厅自然科学基金专项(No.11JK0522)资助项目
关键词
热电材料
原子薄膜
层状材料
thermoelectric nanosheets layered materials
