Strong hybridization of Nb2C with MoS2: a way to reduce contact resistance

The hybridization of MXene materials and transition metal dichalcogenides has a significant impact on heterojunction properties. The transport properties and electronic structure of heterojunctions of semiconducting MoS 2 and metallic MXene Nb 2 C were studied by integrating density functional theory with non-equilibrium Green’s function theory. The hybridization between Nb 2 C and MoS 2 makes the tunneling barrier between the two layers disappear, which can enhance the electron injection efficiency from the Nb 2 C to the MoS 2 . Moreover, the Nb 2 C/MoS 2 heterojunction exhibits a conventional n-type Schottky contact with a barrier height of 0.14 eV, which is significantly lower than the barrier height of 0.29 eV at the Ti/MoS 2 junction. These factors result in a field-effect transistor with a low contact resistance of 138 Ω· μ m and a higher current of 1.09 mA μ m −1 at a bias voltage of 0.3 V applied between the left and right electrodes. Following the application of gate voltage, the I on / I off ratio reaches 1266.