Epitaxial growth of a monolayer WSe<inf>2</inf>-MoS<inf>2</inf> lateral p-n junction with an atomically sharp interface

Abstract

Two-dimensional transition metal dichalcogenides (TMDCs) such as molybdenum sulfide MoS and tungsten sulfide WSe have potential applications in electronics because they exhibit high on-off current ratios and distinctive electro-optical properties. Spatially connected TMDC lateral heterojunctions are key components for constructing monolayer p-n rectifying diodes, light-emitting diodes, photovoltaic devices, and bipolar junction transistors. However, such structures are not readily prepared via the layer-stacking techniques, and direct growth favors the thermodynamically preferred TMDC alloys. We report the two-step epitaxial growth of lateral WSe -MoS heterojunction, where the edge of WSe induces the epitaxial MoS growth despite a large lattice mismatch. The epitaxial growth process offers a controllable method to obtain lateral heterojunction with an atomically sharp interface. 2 2 2 2 2 2