Interfacial atomic engineering of mixed-dimensional van der Waals heterostructures

초록

A critical aspect of van der Waals (vdW) heterostructures is the optical transitions that can be modulated by atomic configurations at their interfaces, though the design space within 2D remains largely limited. Expanding this design space into a 3-dimensional approach by creating mixed-dimensional vdW heterostructures with precisely controlled junction geometry is pivotal for uncovering new excitonic device properties. In this work, we have engineered interfaces of mixed-dimensional vdW heterostructures comprising 1D vdW nanowires and 2D TMD monolayers by manipulating the growth direction of vdW nanowire. Upon interfacing these nanowires onto TMD monolayers, we observed variations in the photoluminescence (PL) energy shift and intensity based on the nanowire's contacting layer orientation. First-principle calculations revealed the band alignment disparities at the heterointerfaces as influenced by the nanowire orientation, providing essential insights into the interface engineering of vdW heterostructures and facilitating the design of innovative ultrathin electronic devices.