Intrinsic limit of contact resistance in the lateral heterostructure of metallic and semiconducting PtSe2

Abstract

High contact resistance (R-c) limits the ultimate potential of two-dimensional (2-D) materials for future devices. To resolve theR(c)problem, forming metallic 1T phase MoS(2)locally in the semiconducting 2H phase MoS(2)has been successfully demonstrated to use the 1T phase as source/drain electrodes in field effect transistors (FETs). However, the long-term stability of the 1T phase MoS(2)still remains as an issue. Recently, an unusual thickness-modulated phase transition from semiconducting to metallic has been experimentally observed in 2-D material PtSe2. Metallic multilayer PtSe(2)and semiconducting monolayer PtSe(2)can be used as source/drain electrodes and channel, respectively, in FETs. Here, we present a theoretical study on the intrinsic lower limit ofR(c)in the metallic-semiconducting PtSe(2)heterostructure through density functional theory (DFT) combined with non-equilibrium Green's function (NEGF). Compared withR(c)in the 1T-2H MoS(2)heterostructure, the multilayer-monolayer PtSe(2)heterostructure can offer much lowerR(c)due to the better capability of providing more transmission modes.