Polarization-mediated electronic characteristics in Sc2CO2-based 2D metal-ferroelectric heterostructures.

Abstract

The preparation of two-dimensional (2D) monolayer Sc2CO2 ferroelectric semiconductor materials provides a promising material candidate for the development of high-performance electronic devices. However, the Schottky barrier present at the electrode/Sc2CO2 interface significantly hinders the efficiency of charge injection. In this work, we propose the utilization of 2D metallic materials as electrodes to form van der Waals (vdW) contacts with ferroelectric Sc2CO2 monolayers, aiming to achieve reduced Fermi-level pinning (FLP) at the interface. By leveraging the ferroelectric polarization reversal in Sc2CO2, we demonstrate a controllable transition from Schottky to Ohmic contact, which is critical for optimizing charge injection efficiency. Additionally, we systematically investigate the polarization-mediated electronic properties of 2D metal/Sc2CO2 interfaces through first-principles calculations.The findings indicate that a transition from Schottky to Ohmic contact can be induced within these heterostructures by manipulating the polarization reversal of Sc2CO2 ferroelectric layers. Notably, the NbS2/Sc2CO2 heterojunction, particularly in the upward polarization state, exhibits the highest carrier tunneling probability among the investigated heterojunctions, making it an optimal electrode for Sc2CO2. These findings are essential for regulating Schottky barriers in 2D metal/ferroelectric semiconductor heterostructures and provide theoretical guidance for designing high-performance field-effect transistors based on 2D metal/Sc2CO2 van der Waals heterostructures.