Precursor Engineering for Synergetic Growth of Superposition Multiheterostructures

2D van der Waals multiheterostructures serve as an extensively studied material due to their unique physical properties. However, the multicomponent heterostructure is difficult to obtain on a large scale and is limited by the conventional method of mechanical stacking, which hinders their potential applications. Here a precursor-modulated chemical vapor deposition strategy is reported for selectively growing vertical multiheterostructures, lateral multiheterostructures, and their combinate stackings. The composition within the heterostructure can be precisely controlled by modulating the concentration of precursors. As a result, four types of heterostructure are resoundingly achieved including graphene/h-BN, graphene/Mo₂C, h-BN/Mo₂C, and graphene/h-BN/Mo₂C superposition multiheterostructure. Morphological, spectroscopic, and atomic-scale structural characterizations are conducted to suggest the high quality of the heterostructures, demonstrating the precise controllability of the strategy. Moreover, both the crystal orientation miss-alignment and Moiré fringes within graphene/Mo₂C vertical heterostructures are also successfully observed benefiting from the fluidity of the liquid copper catalyst under high temperatures. The obtained Mo₂C shows 2D characteristics of superconducting transitions (at 0 T, 6.9 K) as well as a strong anisotropy with magnetic field orientation. The replication of the multiheterostructure customization process in other 2D materials is anticipated, potentially expediting the design of next-generation functional devices.