Hinge-like structure induced unusual properties of black phosphorus and new strategies to improve the thermoelectric performance.
We systematically investigated the geometric, electronic and thermoelectric (TE) properties of bulk black phosphorus (BP) under strain. The hinge-like structure of BP brings unusual mechanical responses such as anisotropic Young's modulus and negative Poisson's ratio. A sensitive electronic structure of BP makes it transform among metal, direct and indirect semiconductors under strain. The maximal figure of merit ZT of BP is found to be 0.72 at 800 K that could be enhanced to 0.87 by exerting an appropriate strain, revealing BP could be a potential medium-high temperature TE material. Such strain-induced enhancements of TE performance are often observed to occur at the boundary of the direct-indirect band gap transition, which can be attributed to the increase of degeneracy of energy valleys at the transition point. By comparing the structure of BP with SnSe, a family of potential TE materials with hinge-like structure are suggested. This study not only exposes various novel properties of BP under strain, but also proposes effective strategies to seek for better TE materials.
College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
Guangzhao
G
Qin
College of Materials Science and Opto-Electronic Technology, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
Qing-Bo
QB
Yan
College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300071, People's Republic of China.
Zhenzhen
Z
Qin
School of Physics, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
Sheng-Ying
SY
Yue
School of Physics, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
Hui-Juan
HJ
Cui
School of Physics, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
Qing-Rong
QR
Zheng
School of Physics, University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
Gang
G
Su