Xiao-Hong Li, Xiang-Ying Su, Rui-Zhou Zhang
College of Physics and Engineering, Henan University of Science and Technology Luoyang 471003 China
RSC Adv. 2019 Sep 3;9(47):27646-27651. doi: 10.1039/c9ra04393d. eCollection 2019 Aug 29.
TiCO MXene is widely considered as a potential candidate material for sensors and optical devices. In this paper, first-principles calculations are performed to investigate the structural and electronic properties of pristine and vacancy defect TiCO monolayer. The results indicate that C-vacancy is energetically more favorable than Ti-vacancy and O-vacancy because of the smaller formation energy of C vacancy. The introduction of vacancy defects results in the transition from semiconductor to metal, and improves the electronic conductivities of TiCO monolayer. The introduction of C and O vacancies causes the Ti-d state to split into several peaks in the energy range of 0 to 2 eV, while the introduction of Ti vacancy makes the Ti-d state weaker and the C-p state stronger. Furthermore, the work function can be effectively engineered by vacancy defects.
TiCO MXene被广泛认为是传感器和光学器件的潜在候选材料。本文进行了第一性原理计算，以研究原始和空位缺陷TiCO单层的结构和电子性质。结果表明，由于C空位的形成能较小，C空位在能量上比Ti空位和O空位更有利。空位缺陷的引入导致从半导体向金属的转变，并提高了TiCO单层的电子电导率。C和O空位的引入使Ti-d态在0至2 eV的能量范围内分裂成几个峰，而Ti空位的引入使Ti-d态减弱，C-p态增强。此外，空位缺陷可以有效地调控功函数。
