Controllable Synthesis of WSe<sub>2</sub>–WS<sub>2</sub> Lateral Heterostructures via Atomic Substitution
Shunhui Zhang, Hang Liu, Fen Zhang, Xiaoming Zheng, Xiangzhe Zhang, Baihui Zhang, Tian Zhang, Zhikang Ao, Xuyang Zhang, Xiang Lan, Yang Xiang-Dong, Mianzeng Zhong, Jia Li, Bo Li, Huifang Ma, Xidong Duan, Jun He, Zhengwei Zhang
Abstract
The atomic substitution in two-dimensional (2D) materials is propitious to achieving compositionally engineered semiconductor heterostructures. However, elucidating the mechanism and developing methods to synthesize 2D heterostructures with atomic-scale precision are crucial. Here, we demonstrate the synthesis of monolayer WSe 2 –WS 2 heterostructures with a relatively sharp interface from monolayer WSe 2 using a chalcogen atom-exchange synthesis route at high temperatures for short periods. The substitution was initiated at the edges of monolayer WSe 2 and the lateral diffuse along the heterointerface, and the reaction can be controlled by the precise reaction time and temperature. The lateral heterostructure and substitution process are studied by Raman and photoluminescence (PL) spectroscopies, electron microscopy, and device characterization, revealing a possible mechanism of strain-induced transformation. Our findings demonstrate a highly controllable synthesis of 2D layered materials through atom substitutional chemistry and provide a simple route to control the atomic structure.