Interface engineering of 1D PbI2 - 2D MoSe2 van der Waals heterostructures

초록

vdW heterostructures based on 2D TMDs have attracted attention due to their superior physical and electrical properties. Especially, the electrical performance of vdW devices is subject to the interface between layered structures. Here, we demonstrate that the interface of PbI2-MoSe2 vdW heterostructure can be engineered by modulating PbI2 stacks. Specifically, VLS method was employed to grow PbI2 vdW nanowires in two different orientations and layer stacking. Upon the dry transfer of PbI2 nanowires onto the CVD-grown MoSe2 monolayers, we confirm that the degree of PL shift and quenching of MoSe2 are dependent on the PbI2 layer stacking orientations relative to the wire axis. A first-principle calculation was employed to reveal the difference in the band alignment at the PbI2/MoSe2 interface according to the PbI2 nanowire orientation. Our results provide important insights into the engineering of vdW heterostructures interfaces and develop new design rule of ultrathin electronic devices.