Two-Dimensional Lateral Heterostructures Made by Selective Reaction on a Patterned Monolayer MoS Matrix.

Two-dimensional (2D) heterostructures have attracted widespread attention for their promising prospects in the fields of electronics and optoelectronics. However, in order to truly realize 2D-material-based integrated circuits, precisely controllable fabrication of 2D heterostructures is crucial and urgently needed. Here, we demonstrate an growth method of MoSe/MoS lateral heterostructures by selective selenization of a laser-scanned, ultrathin oxidized region (MoO) on a monolayer MoS matrix. In our method, monolayer MoS is scanned by a laser with a pre-designed pattern, where the laser-scanned MoS is totally oxidized into MoO. The oxidized region is then selenized in a furnace, while the unoxidized MoS region remains unchanged, delivering a MoSe/MoS heterostructure. Unlike laser direct growth methods, our method separates the laser-scanned process from the selenization process, which avoids the long time of point-by-point selenization of MoS by laser, making the efficiency of the synthesis greatly improved. The formation process of the heterostructure is studied by Raman spectroscopy and Auger electron spectroscopy. This simple and controllable approach to lateral heterostructures with desired patterns paves the way for fast and mass integration of devices based on 2D heterostructures.