Laminated bilayer MoS with weak interlayer coupling.

Laminated bilayer MoS structures are prepared with MoS nanoparticles trapped between two individual MoS layers which can prevent the formation of a true stacking structure held together by van der Waals interaction. The laminated bilayer MoS clearly indicates a weak interlayer coupling with reduced van der Waals interaction between adjacent layers. As the interlayer coupling is insufficient to modify the band structure of MoS, the laminated bilayer MoS can retain the direct bandgap structure of an isolated monolayer. Furthermore, by controlling the size of the MoS nanoparticles trapped in between, the interlayer distance and interlayer coupling of bilayer MoS structures can be engineered in a wide range, resulting in different bandgap behaviors. This finding is extremely important as it provides an effective approach to fabricate bandgap engineered bilayer MoS structures, which is a crucial step forward to making multi-layer MoS-based p-n junctions and homo/hetero-structures, and thus advanced electronic devices, especially optoelectronic devices. This approach is applied to not only bilayer MoS structures, but also other layer structured two-dimensional materials.