Characteristics of electrical metal contact to monolayer WSe2

Abstract The extremely high contact resistance often observed in the interface between two-dimensional p-type transition-metal dichalcogenides and metal electrodes with a high work function, such as Ni, Au, and Pd, is usually correlated with poor device performance. Here, we report the quantitative contact resistance and the Schottky barrier height of chemical vapor deposition grown-monolayer tungsten diselenide (WSe2)-based field-effect transistors (FETs) with Au electrodes; these values are obtained by using the transmission line method and by analyzing the low-temperature transport properties, respectively. Back-gate monolayer WSe2 FETs with Au electrodes exhibit p-type behavior, with a mobility, on/off ratio, contact resistance, and Schottky barrier height of 0.2 cm2/V•s, 6 × 105, 0.495 M Ω · μ m, and 38 meV, respectively.