SINGLE LAYER ReS2H2 : STABILITY, RAMAN ACTIVITY AND ELECTRONIC PROPERTIES

Özet

In this study, the structural, vibrational and electronic properties of the hydrogenated single layer of ReS2 are investigated by performing the first principle calculations based on density functional theory. We found that the characteristic properties of the monolayer ReS2 can be manipulated upon the hydrogen functionalization. As the monolayer ReS2, the ReS2H2 has distorted 1Tphase; however, the bonding in Re slab significantly varies with the hydrogenation. Our results demonstrate that the full-surface hydrogenation leads to an expansion in lattice and the Re4 tetramer-chains in the monolayer ReS2 are separated into two dimers in the hydrogenated monolayer. It is calculated that the dynamically stable monolayer of ReS2H2 has 26 Raman-active vibrational modes. Constant volume specific heat calculations are also performed and the results indicate that at high temperature, the monolayer ReS2 approaches to limit of 3R before the monolayer ReS2H2. By performing the electronic band structure calculations, it is shown that when the ReS2 surface is fully hydrogenated, there occurs a direct to indirect band gap transition and the semiconducting hydrogen-induced monolayer has a band gap of 0.74 eV.