Bipolar Nb3Cl8 Field Effect Transistors

Abstract

Field effect transistors based on few-layered van der Waals transition metal halide (TMH) Nb3Cl8 are studied in this work. Few-layered Nb3Cl8 exhibits typical N-type semiconducting behavior controlled by a Si gate, with the electrical signal enhancing as the thickness increases from 4.21 nm to 16.7 nm. Moreover, we find that the tunability of few-layered Nb3Cl8 FETs’ electrical transport properties can be significantly augmented through the use of an ionic liquid gate (or electrical double layer, EDL). This enhancement leads to a substantial increase in the on–off ratio by approximately a factor of 102, with the transfer curve modulated into a bipolar fashion. The emergence of such bipolar tunable characteristics in Nb3Cl8 FETs serves to enrich the electronic properties within the transition metal halide family, positioning Nb3Cl8 as a promising candidate for diverse applications spanning transistors, logic circuits, neuromorphic computing and spintronics.