Anion charge density disturbance induces in-plane instabilities within 2D lateral heterojunction of TMD: An atomic view

Two-dimensional (2D) transition-metal dichalcogenides (TMD) heterostructure semiconductors are emerging as the potential candidates for broad applications due to their flexible modulations of the electronic behaviors. However, the investigations of these TMD heterostructure semiconductors usually only limit to the synthesis approach and opt-electronic properties, lacking the in-depth guidelines from the atomic exploration of the formation and control of the disorder. Beyond the conventional disorder induced by the local fluctuations of inherent material properties such as chemical and structural composition, the fundamental concept of long-range phonon-based disorder has been identified in the single-layered TMD homogeneous structure [Nat. Nanotechnol. 14, 832 (2019).]. Herein, we propose the essential long-range p-p coupling effect in the more complex WS₂/WSe₂ lateral heterojunction systems, which leads to the formation of ripple in the macroscopic structure. The unique lattice dynamic near the interface edge initiates the long-range disorder from the atomic view. Such long-range p-p couplings are confirmed by the large scale simulations by Forcite and the actual experimental scale simulations by COMSOL, supporting their pivotal role in modulating the electronic behaviors. This work has compensated the knowledge gap between the theoretical investigation and experimental synthesis, which is essentially beneficial for the future fabrication of 2D heterostructure semiconductors with superior performance.