Tuning electronic and transport properties of MoS2/Ti2C heterostructure by external strain and electric field

Abstract

We investigated the effects of external strain and electric field on the electronic, transport, and thermoelectric properties of MoS2/Ti2C heterostructure by using the first-principles method. Its electronic properties can be effectively tuned by applying uniaxial tensile strain, biaxial tensile strain, and vertical electric field, and exhibits different behaviour. An obvious band gap between the valence bands I and II is observed under external field. Upon application of tensile strain, energy bands become more dispersive, inducing the increase in conductivity. However, when the coupling of tensile strain and vertical electric field was imposed, energy bands become more flat, leading to the decrease in conductivity. Based on the calculated energy bands, the effect of external field on the carrier effective mass was also discussed. Furthermore, the change in electronic properties affects the transport and thermoelectric properties of MoS2/Ti2C heterostructure. Tensile strain enhances its transport properties. However, the transport properties of MoS2/Ti2C heterostructure is weakened under the application of vertical electric field. Comparing with no external field, the thermoelectric power factor is decreased under external field.