Oxygenation of monolayer gallium monochalcogenides: Design of two-dimensional ternary Ga 2 X O structures ( X = S , Se , Te )

摘要: The possibility of breaking structural symmetry with realization Janus monolayers offers new possibilities in the field two-dimensional (2D) materials, and various ternary systems including class group-III monochalcogenides have been suggested. However, interaction oxygen was shown to modify optoelectronic properties gallium monochalcogenides, design as a third component has not considered yet. In this paper, we investigate 2D ${\mathrm{Ga}}_{2}X\text{O}$ ($X=\mathrm{S},\mathrm{Se},\mathrm{Te}$) by using first-principles calculations. Phonon spectra analysis molecular dynamics simulations indicate that while ${\mathrm{Ga}}_{2}\mathrm{SO}$ ${\mathrm{Ga}}_{2}\mathrm{SeO}$ are stable even at high temperatures ${\mathrm{Ga}}_{2}\mathrm{TeO}$ is dynamically unstable. Inclusion makes less brittle when compared their binary constituents. While $\mathrm{Ga}X$ indirect band gaps, become direct band-gap semiconductors gap can be further tuned tensile/compressive strain. Additionally, depending on type system, strong optical absorption within infrared, visible, and/or ultraviolet region also predicted. Finally, electronic bilayers examined monolayers. Our results only predict structures but suggest them promising materials for applications.