Polymorphism in two-dimensional tellurium crystals*

Elemental layered materials have attracted much attention because they exhibit unique physical phenomena and a wide range of electronic properties ranging from metallic and semi-metallic to semiconducting. Recent experimental reports describe the vacuum-deposition-based synthesis and partial characterization of two-dimensional polymorphs of tellurium, dubbed tellurene. In this work, we perform quantum molecular dynamics (QMD) simulations to more thoroughly explore the atomic structure of tellurene. We identify several tellurene polymorphs that are consistent with experimental observations. Furthermore, we find several new tellurene polymorphs, which may be realized under tension.