The effect of vacancy defect on quantum capacitance, electronic and magnetic properties of Sc2CF2 monolayer

Abstract

AbstractTwo‐dimensional (2D) MXene materials have attracted much attention in recent years because of their excellent properties. In this paper, we theoretically investigated the quantum capacitance, electronic and optical properties of pristine Sc2CF2 and the vacancy‐doping Sc2CF2 monolayers by first principles calculations. Pristine Sc2CF2 is the most stable structure among the four investigated systems according to the analysis of binding energy, and the introduction of vacancy does not improve the stability of the system. The introduction of vacancy produced the defect energy levels, which pass through the Fermi energy level and result in the semiconductor–metal transition. For Pristine Sc2CF2, the introduction of VSc results in the strong magnetism with 1.0 μB, which is mainly from the contribution of C‐pz, Sc‐dz2, Sc‐dxz states. The analysis of optical properties indicates that the introduction of the vacancy not only makes the system more sensitive to the infrared light, but also improves the reflectivity, especially in the infrared region. The introduction of vacancy improves the Cdiff of the systems at 0 V, and drastically increases the maximum Cint of the vacancy‐doping systems. Charge transfer is further explored.