Qian Gao,Wenbin Li,Caiyun Chen,Kehui Wu,Zhenpeng Hu,Lan Chen

Abstract

The performance of devices based on two-dimensional (2D) materials is fundamentally limited by their contacts with metal electrodes. Thus, the realization of covalent bonding between 2D materials and metal electrode presents a potential solution. Here, we fabricate a novel type of interface between 2D boron sheet (borophene) with one-dimensional (1D) silver chains on Ag(111) surface. Using scanning tunneling microscopy (STM) and density functional theory (DFT), the atomic structures of the boron-silver interface are identified, which indicate 4-fold superlattice modulation with a period of ∼1.20 nm along the borophene edges due to the compressive strain field at the interface. Electronic structure analysis reveals charge transfer and the formation of polar covalent Ag–B bonds at the interface, facilitating efficient electron injection reminiscent of an Ohmic contact. This work establishes a substrate-enabled, stress-driven pathway for creating atomically precise 2D materials/metal interfaces, providing a model platform for exploring low-dimensional quantum phases and the fundamental interface engineering.

Paper Linkage:https://pubs.acs.org/doi/10.1021/jacs.5c23239