Electronic and Magnetic Properties of Fluorinated Transition Metal Dichalcogenide 1T-MX2F2 (X = S, Se, Te) Monolayers.

Two-dimensional transition metal dichalcogenides (TMDCs) have attracted worldwide attention due to their rich physical and chemical properties. How to regulate their electronic structures to meet different application requirements is a crucial issue. In this work, based on first-principle calculations, we demonstrate that surface fluorination can be a powerful method for tailoring the electronic and magnetic properties of TMDC monolayers. The fluorinated T-MX2F2 (X = S, Se, Te) monolayers cover semiconductors, half-metals, semimetals, and half-semimetals. In particular, monolayer T-CrS2F2 is a half-semimetal, and the spin-orbit coupling effect changes it to a quantum anomalous Hall insulator. Monolayer T-HfS2F2 is a non-magnetic semimetal, and monolayer T-CoS2F2 is a half-metal. These findings not only suggest that fluorination can dramatically alter the electronic properties of two-dimensional TMDCs but also provide a new research platform for developing nanoelectronic devices.