Direct Epitaxial Synthesis of Selective Two-Dimensional Lateral Heterostructures

Two-dimensional (2D) heterostructured or alloyed monolayers composed of transition metal dichalcogenides (TMDCs) have recently emerged as promising materials with great potential for atomically thin electronic applications. However, fabrication of such artificial TMDC heterostructures with a sharp interface and a large crystal size still remains a challenge because of the difficulty in controlling various growth parameters simultaneously during the growth process. Here, a facile synthetic protocol designed for the production of the lateral TMDC heterostructured and alloyed monolayers is presented. A chemical vapor deposition approach combined with solution-processed precursor deposition makes it possible to accurately control the sequential introduction time and the supersaturation levels of the vaporized precursors, and thus reliably and exclusively produces selective and heterogeneous epitaxial growth of TMDC monolayer crystals. In addition, unique TMDC core/shell heterostructured (MoS2/alloy, alloy/WS2...