Laminated bilayer MoS2 with weak interlayer coupling

Abstract

Laminated bilayer MoS₂ structures are prepared with MoS₂ nanoparticles trapped between two individual MoS₂ layers which can prevent the formation of a true stacking structure held together by van der Waals interaction. The laminated bilayer MoS₂ 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 MoS₂, the laminated bilayer MoS₂ can retain the direct bandgap structure of an isolated monolayer. Furthermore, by controlling the size of the MoS₂ nanoparticles trapped in between, the interlayer distance and interlayer coupling of bilayer MoS₂ 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 MoS₂ structures, which is a crucial step forward to making multi-layer MoS₂-based p–n junctions and homo/hetero-structures, and thus advanced electronic devices, especially optoelectronic devices. This approach is applied to not only bilayer MoS₂ structures, but also other layer structured two-dimensional materials.