Herein, using first‐principles calculations the structural and electronic properties of the Ti₂CO₂ MXene monolayer with and without oxygen vacancies are systematically investigated with different defect concentrations and patterns, including partial, linear, local, and hexagonal types. The Ti₂CO₂ monolayer is found to be a semiconductor with a bandgap of 0.35 eV. The introduction of oxygen vacancies tends to increase the bandgap and leads to electronic phase transitions from nonmagnetic semiconductors to half‐metals. Moreover, the semiconducting characteristic of O‐vacancy Ti₂CO₂ can be adjusted via electric fields, strain, and F‐atom substitution. In particular, an electric field can be used to alter the nonmagnetic semiconductor of O‐vacancy Ti₂CO₂ into a magnetic one or into a half‐metal, whereas the electronic phase transition from a semiconductor to metal can be achieved by applying strain and F‐atom substitution. The results provide a useful guide for practical applications of O‐vacancy Ti₂CO₂ monolayers in nanoelectronic and spinstronic nanodevices.

中文翻译：

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Ti2CO2 MXene单层中的氧空位：门控电压，机械应变和原子杂质的影响

在本文中，使用第一性原理计算系统地研究了具有和不具有氧空位的Ti ₂ CO ₂ MXene单层的结构和电子性质，其具有不同的缺陷浓度和图案，包括部分，线性，局部和六边形类型。发现Ti ₂ CO ₂单层是带隙为0.35eV的半导体。氧空位的引入往往会增加带隙，并导致从非磁性半导体到半金属的电子相变。此外，O-空位Ti ₂ CO ₂的半导体特性可以通过电场，应变和F原子取代来调节。特别是，电场可用于将O型空位Ti ₂ CO ₂的非磁性半导体转变为磁性的一种或半金属，而通过施加应变和电场可实现从半导体到金属的电子相变。 F原子取代。该结果为O-空位Ti ₂ CO ₂单层在纳米电子和自旋电子纳米器件中的实际应用提供了有用的指导。