A review on the research progress of tailoring photoluminescence of monolayer transition metal dichalcogenides

Abstract

The unique electrical and optical properties in atomically thin two-dimensional (2D) transition metal dichalcogenides (TMDCs) have recently attracted huge research interests. Synthetic methods, such as chemical vapor deposition (CVD), provide scalable way to produce 2D TMDCs layers with good controllability for optoelectronics applications. However, intricate defects including point defects, dislocations, grain boundaries, and type of edges are inevitably formed during the synthetic reactions. The TMDCs monolayers grown by CVD method could incorporate structure defects such as chalcogen and metal vacancies to determine their electrical and optical properties. In this review, we present the recent development in the structure defects characterization and repairing. We further provide insights into the crystal lattices and their optical properties in the TMDCs layers. Based on these fundamental understanding of the photoluminescence (PL) evolution, monolayer lattice structures and chemical compositions are being established. A better understanding on the generation, control and passivation of defects lead to the field of so called defect engineering in TMDCs layers.