First-principles study on the electronic, optical, and transport properties of monolayer α - and β -GeSe

作者：Yuanfeng Xu, Hao Zhang, Hezhu Shao, Gang Ni, Jing Li, Hong-Liang Lü, Rongjun Zhang, Bo Peng, Yong‐yuan Zhu, Heyuan Zhu, Costas M. Soukoulis · 发表于：Physical review. B./Physical review. B · 年份：2017 · DOI：10.1103/physrevb.96.245421 · 被引用次数：117 · 研究领域：2D Materials and Applications、Graphene research and applications、MXene and MAX Phase Materials

The extraordinary properties and the novel applications of black phosphorene induce the research interest in the monolayer group-IV monochalcogenides. Here using first-principles calculations, we systematically investigate the electronic, transport, and optical properties of monolayer $\ensuremath{\alpha}$- and $\ensuremath{\beta}$-GeSe, revealing a direct band gap of 1.61 eV for monolayer $\ensuremath{\alpha}$-GeSe and an indirect band gap of 2.47 eV for monolayer $\ensuremath{\beta}$-GeSe. For monolayer $\ensuremath{\beta}$-GeSe, the electronic/hole transport is anisotropic, with an extremely high electron mobility of $2.93\ifmmode\times\else\texttimes\fi{}{10}^{4}\phantom{\rule{0.16em}{0ex}}{\text{cm}}^{2}/\text{V}\phantom{\rule{0.16em}{0ex}}\text{s}$ along the armchair direction, comparable to that of black phosphorene. Furthermore, for $\ensuremath{\beta}$-GeSe, robust band gaps nearly independent of the applied tensile strain along the armchair direction are observed. Both monolayer $\ensuremath{\alpha}$- and $\ensuremath{\beta}$-GeSe exhibit anisotropic optical absorption in the visible spectrum.