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

Abstract

The preparation of two-dimensional (2D) monolayer Sc₂CO₂ferroelectric semiconductor materials provides a promising material candidate for the development of high-performance electronic devices. However, the Schottky barrier present at the electrode/Sc₂CO₂interface 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 Sc₂CO₂monolayers, aiming to achieve reduced Fermi-level pinning 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/Sc₂CO₂interfaces 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 Sc₂CO₂ferroelectric layers. Notably, the NbS₂/Sc₂CO₂heterojunction, 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/Sc₂CO₂vdW heterostructures.