Misorientation angle-dependent phase transformation in van der Waals multilayers via electron-beam irradiation
Journal
ADV MATER
Date
2018.03.24
Abstract
One intriguing feature of van der Waals materials is the layer thickness and misorientation angle dependence that involve stark optical gain and electrical transport modulation. Yet, the phase transformation modulated by the misorientation angle has never been accessible to date. Here, we report misorientation angle-dependent phase transformation of multilayer MoS2 via in situ electron beam irradiation. AA’ stacked-bilayer MoS2 undergoes structural transformation from 2H semiconducting to 1T’ metallic phase similar to monolayer MoS2, which is confirmed via in situ transmission electron microscopy. Meanwhile, non-AA’ stacking which has no local AA’ stacking order in Moire pattern does not reveal such a phase transformation. While collective sliding motion of chalcogen atoms easily occurs during transformation in AA’ stacking, such a collective motion in non-AA’ stacking is suppressed by weak van der Waals strength and furthermore by the interlocked chalcogen atoms at different orientations, which unfavor their kinetics by the increased entropy of mixing.