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

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 V_ds and 55.7 meV for positive V_ds 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.