Abstract
A Schottky barrier, formed in the contact of a two-dimensional (2D) semiconductor and metal electrode, seriously degrades device performance. Herein, we propose a dipole-engineering strategy to regulate the electronic contact properties of a 2D polar X (X = , , ) and graphene () van der Waals interface. Owing to the mirror asymmetry of X, we construct seven vertical heterostructures in the form of X- and X. Tunable Schottky barrier height and contact type can be obtained by using different atomic terminals to contact with . Based on the first-principles calculations, the dipole and its associated potential step are found to be responsible for the regulating effect. Moreover, owing to the remarkable properties of the - heterostructure, such as Ohmic contact and low tunneling barrier, we design an optoelectronic field-effect transistor, which exhibits considerable responsivity (0.089 ) and external quantum efficiency (28.57%). Our findings further confirm that regulating the electronic contact properties by the dipole in the heterostructure is a feasible strategy, which provides meaningful guidance for designing high-performance electronic and optoelectronic devices.
- Received 21 October 2021
- Revised 14 March 2022
- Accepted 14 April 2022
DOI:https://doi.org/10.1103/PhysRevApplied.17.054009
© 2022 American Physical Society