Simulation Evidence of Hexagonal-to-Tetragonal ZnSe Structure Transition: A Monolayer Material with a Wide-Range Tunable Direct Bandgap.

ABSTRACT: 2D material with tunable direct bandgap in the intermediate region (i.e., ≈2-3 eV) is key to the achievement of high efficiency in visible-light optical devices. Herein, a simulation evidence of structure transition of monolayer ZnSe from the experimental pseudohexagonal structure to the tetragonal structure (t-ZnSe) under lateral pressure is shown, suggesting a possible fabrication route to achieve the t-ZnSe monolayer. The as-produced t-ZnSe monolayer exhibits highly tunable bandgap under the biaxial strains, allowing strain engineering of t-ZnSe's bandgap over a wide range of 2-3 eV. Importantly, even under the biaxial strain up to 7%, the t-ZnSe monolayer still keeps its direct-gap property in the desirable range of 2.40-3.17 eV (corresponding to wavelength of green light to ultraviole

SUBMITTER: Li L 

PROVIDER: S-EPMC5061093 | biostudies-literature | 2015 Dec

REPOSITORIES: biostudies-literature