Monolayer WS2 Lateral Homosuperlattices with Two-dimensional Periodic Localized Photoluminescence

ACS Nano. 2022 Jan 25;16(1):597-603. doi: 10.1021/acsnano.1c07803. Epub 2021 Dec 17.

Abstract

Homojunctions and homosuperlattices are essential structures and have been widely explored for use in advanced electronic and optoelectronic devices. However, artificially manipulating crystalline phases in two-dimensional (2D) monolayers is still challenging, especially when attempting to engineer lateral homogeneous junctions in a single monolayer of transition metal dichalcogenides (TMDs). Herein, we demonstrate a lateral homosuperlattice (MLHS) with alternating 1T and 2H domains in a 2D WS2 monolayer plane. In MLHSs, the 2H domains, which are laterally localized and isolated by potential wells, manifest junction interfaces and irradiated photoluminescence (PL) with a lateral periodic distribution in the two-dimensional plane. The studies on MLHSs here can provide further understanding of lateral homojunctions and homosuperlattices in a monolayer plane, providing an alternative route to modulate optical and electronic behaviors in TMD monolayers.

Keywords: 1T and 2H phases; WS2; homosuperlattices; photoluminescence; potential wells.