PVD growth of spiral pyramid-shaped WS on SiO/Si driven by screw dislocations.

Atomically thin layered transition metal dichalcogenides (TMDs), such as MoS and WS, have been getting much attention recently due to their interesting electronic and optoelectronic properties. Especially, spiral TMDs provide a variety of candidates for examining the light-matter interaction resulting from the broken inversion symmetry, as well as the potential new utilization in functional optoelectronic, electromagnetic and nanoelectronics devices. To realize their potential device applications, it is desirable to achieve controlled growth of these layered nanomaterials with a tunable stacking.