Electronic and transport properties for Ti3C2O2 under the influence of a vertical electric field and stacking number

The effect of a vertical electric field on the structural, electronic, and transport properties of Ti3C2O2 with varying numbers of layers was systematically investigated by means of the first-principles method. This result demonstrated that the related properties of Ti3C2O2 could be effectively tuned by the stacking number and the vertical electric field. When the vertical electric field increased to 2 V/angstrom, the energy bands of the monolayer and multilayers of the Ti3C2O2 were separated obviously. However, the external vertical field could not open a band gap in the two dimensional Ti3C2O2. Its transmission coefficients and thermoelectric power factors increased linearly with the increase of the stacking number. It revealed that the trilayer Ti3C2 had the potential of being a thermoelectric material. The transport properties for a dualgated Ti3C2O2 model were examined using non-equilibrium Green's functions. The results clearly confirmed that the vertical electric field could manipulate the transport properties of Ti3C2O2, and the corresponding mechanisms are also discussed in detail. (C) 2018 Elsevier B.V. All rights reserved.