A theoretical study of the electrical contact between metallic and semiconducting phases in monolayer MoS2

作者：Paz Wendel S^*; Palacios J J

来源：2D Materials, 2017, 4(1): 015014.

DOI：10.1088/2053-1583/4/1/015014

• MoS2
• lateral heterojunction
• contact resistance
• quantum transport
• DFT

We present a theoretical study of the electrical contact between the two most common crystallographic phases of MoS2 monolayer crystals: the stable semiconducting 2H phase and the metastable metallic 1T phase. A density functional theory (DFT) study of the electronic structure of interface between the two phases shows a higher Schottky barrier for electrons than for holes for the undoped 2H phase. Charge transfer from the 1T to the 2H phase occurs, but, as expected for a one-dimensional contact, the generated dipole potential decays away from the interface and the naive Schottky-Mott band-alignment picture is recovered away from the interface. The decay length of the dipole potential turns out to be larger for the zigzag interface than for the armchair interface due to the different penetration of the edge states into the bulk. Tight-binding quantum transport calculations aided by the DFT results generically confirm a low contact resistance in the range of approximate to 200-400 Omega mu m, as experimentally reported. Furthermore, the contact resistance is predicted to be smaller at the armchair interface for electron injection and, on the contrary, smaller for hole injection at the zigzag interface.

• 出版日期2017-3