Affiliation:
1. School of Science State Key Laboratory of Organic Electronics and Information Displays & Institute of Advanced Materials (IAM) and College of Electronic and Optical Engineering Nanjing University of Posts & Telecommunications Nanjing 210023 China
2. College of Physics Science and Technology Yangzhou University Yangzhou 225002 China
3. Institute for Computational Materials Science Joint Center for Theoretical Physics (JCTP) School of Physics and Electronics Henan University Kaifeng 475004 China
Abstract
Abstract2D metal and semiconductor materials provide a promising solution to realize Ohmic contacts by suppressing the strong Fermi level pinning (FLP) effect due to without dangling bonds. However, the 2D metal‐semiconductor Van der Waals (vdW) interfaces induce an inevitable tunnel barrier, significantly restraining the injection of charge carriers into the conduction channel. Herein, by replacing the vdW bond with the covalent bond in interfaces, the Ohmic and tunneling‐barrier‐inhibition contacts are realized simultaneously based on the 2D XSi2N4 (X = Cr, Hf, Mo, Ti, V, Zr) semiconductor and the 2D Mxene metal family. Taking 60 2D Mxene‐XSi2N4 contacts as examples, although the vdW‐type contacts exhibit Ohmic contacts, the tunneling probability (PTB) can be as low as 0.4%, while the PTB can increase to 88.09% by removing the Mxene terminations at the adjacent interface to form the covalent bond. The weak FLP and Ohmic contacts are retained at covalent bond interfaces since the outlying Si─N sublayer protects the band‐edge electronic states of XSi2N4 semiconductors. This work provides a straightforward strategy for advancing high‐performance and energy‐efficient 2D electronic nanodevices.
Funder
China Postdoctoral Science Foundation
National Natural Science Foundation of China