Ferroelectric\nField-Effect Transistors Based on MoS₂ and CuInP₂S₆ Two-Dimensional van der\nWaals Heterostructure

Abstract

We\ndemonstrate room-temperature ferroelectric field-effect transistors\n(Fe-FETs) with MoS₂ and CuInP₂S₆ two-dimensional\n(2D) van der Waals heterostructure. The ferroelectric CuInP₂S₆ is a 2D ferroelectric insulator, integrated on top\nof MoS₂ channel providing a 2D/2D semiconductor/insulator\ninterface without dangling bonds. The MoS₂- and CuInP₂S₆-based 2D van der Waals heterostructure Fe-FETs\nexhibit a clear counterclockwise hysteresis loop in transfer characteristics,\ndemonstrating their ferroelectric properties. This stable nonvolatile\nmemory property can also be modulated by the back-gate bias of the\nMoS₂ transistors because of the tuning of capacitance matching\nbetween the MoS₂ channel and the ferroelectric CuInP₂S₆, leading to the enhancement of the on/off current\nratio. Meanwhile, the CuInP₂S₆ thin film also\nshows resistive switching characteristics with more than four orders\nof on/off ratio between low- and high-resistance states, which is\nalso promising for resistive random-access memory applications.