Reaction-Kinetics-Driven Epitaxy of Wafer-Scale WS 2 by Molten Precursor Engineering

grows through sustained lateral propagation, producing crystallographically aligned monolayer wafers with narrow excitonic linewidths ascribed to suppressed disorder. First-principles calculations show that the molten precursor shifts the rate-limiting step from oxide conversion to edge incorporation, while sodium-mediated attachment lowers the propagation barrier. This work establishes precursor-state engineering as a general route to overcome reaction-limited regimes in tungsten-based two-dimensional TMDCs epitaxy.