Kahraman, ZeynepBaşkurt, MehmetYağmurcukardeş, NesliChaves, A.Şahin, Hasan2021-01-242021-01-2420210169-43321873-5584https://doi.org/10.1016/j.apsusc.2020.148064https://hdl.handle.net/11147/10198First-principles calculations are performed in order to investigate the formation of Janus structures of single-layer TaSe2. The structural optimizations and phonon band dispersions reveal that the formation and stability of hydrogenated (HTaSe2), fluorinated (FTaSe2), and the one-side hydrogenated and one-side fluorinated (Janus-HTaSe2F) single-layers are feasible in terms of their phonon band dispersions. It is shown that bare metallic single-layer TaSe2 can be turned into a semiconductor as only one of its surface is functionalized while it remains as a metal via its two surfaces functionalization. In addition, the semiconducting nature of single-layers HTaSe2 and FTaSe2 and the metallic behavior of Janus TaSe2 are found to be robust under applied uniaxal strains. Further analysis on piezoelectric properties of the predicted single-layers reveal the enhanced in-plane and out-of-plane piezoelectricity via formed Janus-HTaSe2F. Our study indicates that single-layer TaSe2 is a suitable host material for surface functionalization via fluorination and hydrogenation which exhibit distinctive electronic and vibrational properties. © 2020 Elsevier B.V.eninfo:eu-repo/semantics/closedAccessAsymmetric surface functionalizationDensity functional theoryJanus single-layersTaSe2Article2-s2.0-8509270456910.1016/j.apsusc.2020.148064