Ternary Transition Metal Chalcogenide Nb₂Pd₃Se₈: A New Candidate of 1D Van der Waals Materials for Field-Effect Transistors

In this work, high-quality 1D van der Waals (vdW) Nb₂Pd₃Se₈ is synthesized, showing an excellent scalability from bulk to single-ribbon due to weakly bonded repeating unit ribbons. The calculation of electronic band structures confirmed that this novel Nb₂Pd₃Se₈ is a semiconducting material, displaying indirect-to-direct bandgap transition with decreasing the number of unit-ribbons from bulk to single. Field effect transistors (FETs) fabricated on the mechanically exfoliated Nb₂Pd₃Se₈ nanowires exhibit n-type transport characteristics at room temperature, resulting in the values for the electron mobility and I_on/I_off ratio of 31 cm² V⁻¹ s⁻¹ and ≈10⁴, respectively. Through transport measurements at various temperatures from room temperature down to 90 K, it is confirmed that Nb₂Pd₃Se₈ FETs can achieve negligible Schottky barrier height (SBH) for the Au contacts at the temperature range, displaying clear ohmic contact characteristics. Furthermore, top-gated FETs fabricated with the Al₂O₃ dielectric layer are studied simultaneously with back-gated FETs.