Quantification of Schottky barrier height and contact resistance of a Au electrode on multilayer WSe2

Abstract

Two-dimensional transition-metal dichalcogenide (TMD) device performance is significantly affected by the contact resistance of Schottky contacts at the p-type TMD–metal–electrode interface. The contact resistance and the Schottky barrier height (SBH) of a chemical-vapor-deposition-grown multilayer WSe2 film-based field-effect transistor with Au electrodes were investigated. The experimentally measured and calculated SBH was determined from temperature-dependent current–voltage measurements and thermionic emission model. The transfer length method was employed to investigate the contact resistance between the WSe2 and the Au electrode. SBH values of 56 meV for negative Vds and 55.7 meV for positive Vds and a contact resistance of 12 kΩ·μm were found. An ion-gel-gated field-effect transistor based on multilayer WSe2 exhibited ambipolar behavior with a mobility and an on/off ratio of 1.09 × 10 - 2 cm2/V s and 103, respectively.