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

• Published in: Nanoscale 2020-07, Vol.12 (27), p.14636-14641
• Main Authors: Yang, Eunyeong, Seo, Jae Eun, Seo, Dongwook, Chang, Jiwon
• Format: Article
• ISSN: 2040-3364; 2040-3372
• DOI: 10.1039/d0nr03001e

High contact resistance ( R c ) limits the ultimate potential of two-dimensional (2-D) materials for future devices. To resolve the R 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 PtSe 2 . 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 of R c in the metallic-semiconducting PtSe 2 heterostructure through density functional theory (DFT) combined with non-equilibrium Green's function (NEGF). Compared with R c in the 1T-2H MoS 2 heterostructure, the multilayer-monolayer PtSe 2 heterostructure can offer much lower R c due to the better capability of providing more transmission modes. Low contact resistance can be achieved in the metallic and semiconducting PtSe 2 lateral heterostructure through the thickness-dependent phase transition in PtSe 2 .