Defects in layered vapor-phase grown MOS2

摘要

Molybdenum disulfide (MoS) is a layered two-dimensional (2D) semiconducting material with a band-gap ranging from 1.3 eV in bulk to 1.88 eV in mono-layer [1]. This transition metal dichalcogenide (TMD) is being studied as a potential material for nanoelectronics and optoelectronics [2], [3]. Most of the research on electronic devices based on MoS published so far is naturally focused on lateral (in-plane) transport properties. In this work, we investigate MoS2 with respect to its material properties in vertical direction, with a potential application as a dielectric barrier material for vertical heterosturcture devices, such as Graphene-base Hot Electron Transistors (GBTs) [4], [5]. Its low band gap compared to available oxides and its low band offset with respect to silicon (Si) could yield an efficient GBT emission barrier [6]. We discuss Si/MoS/Metal structures based on C-V measurements and propose the method for probing the electronic properties, including defects and interface states, of MoS and other TMDs.