One-dimensional van der Waals stacked p-type crystal Ta₂Pt₃Se₈ for nanoscale electronics

Abstract

Recently, ternary transition metal chalcogenides Ta₂X₃Se₈ (X = Pd or Pt) have attracted great interest as a class of emerging one-dimensional (1D) van der Waals (vdW) materials. In particular, Ta₂Pd₃Se₈ has been actively studied owing to its excellent charge transport properties as an n-type semiconductor and ultralong ballistic phonon transport properties. Compared to subsequent studies on the Pd-containing material, Ta₂Pt₃Se₈, another member of this class of materials has been considerably less explored despite its promising electrical properties as a p-type semiconductor. Herein, we demonstrate the electrical properties of Ta₂Pt₃Se₈ as a promising channel material for nanoelectronic applications. High-quality bulk Ta₂Pt₃Se₈ single crystals were successfully synthesized by a one-step vapor transport reaction. Scanning Kelvin probe microscopy measurements were used to investigate the surface potential difference and work function of the Ta₂Pt₃Se₈ nanoribbons of various thicknesses. Field-effect transistors fabricated on exfoliated Ta₂Pt₃Se₈ nanoribbons exhibited moderate p-type transport properties with a maximum hole mobility of 5 cm² V^-1 s^-1 and an <i>I</i>_on/<i>I</i>_off ratio of >10⁴. Furthermore, the charge transport mechanism of Ta₂Pt₃Se₈ was analyzed by temperature-dependent transport measurements in the temperature range from 90 to 320 K. To include Ta₂Pt₃Se₈ in a building block for modern 1D electronics, we demonstrate p-n junction characteristics using the electron beam doping method.