Pulsed laser deposition for the synthesis of monolayer WSe2

Atomically thin films of WSe2 from one monolayer up to 8 layers were deposited on an Al2O3 r-cut (1 (1) over bar 02) substrate using a hybrid-Pulsed Laser Deposition (PLD) system where a laser ablation of pure W is combined with a flux of Se. Specular X-ray reflectivities of films were analysed and were consistent with the expected thickness. Raman measurement and atomic force microscopy confirmed the formation of a WSe2 monolayer and its spatial homogeneity over the substrate. Grazingincidence X-ray diffraction uncovered an in-plane texture in which WSe2 [10 (1) over bar0] preferentially aligned with Al2O3 [11 (2) over bar0]. These results present a potential to create 2D transition metal dichalcogenides by PLD, where the growth kinetics can be steered in contrast to common growth techniques like chemical vapor deposition and molecular beam epitaxy. Published by AIP Publishing.