Wafer-scale Programmed Assembly of One-atom-thick Crystals

Abstract: Crystalline films offer various physical properties based on the modulation of their thicknesses and atomic structures. The layer-by-layer assembly of atomically thin crystals provides powerful means to arbitrarily design films at the atomic-level, which are unattainable with existing growth technologies. However, atomically-clean assembly of the materials with high scalability and reproducibility remains challenging. We report programmed crystal assembly (PCA) of graphene and monolayer hexagonal boron nitride (ML hBN), assisted by van der Waals interactions, to form wafer-scale films of pristine interfaces with near-unity yield. The atomic configurations of the films are tailored with layer-resolved compositions and in-plane crystalline orientations. We demonstrate batch-fabricated tunnel device arrays with modulation of the resistance over orders of magnitude by thickness-control of the hBN barrier with single-atom precision, and large-scale, twisted multilayer graphene with programmable electronic band structures and crystal symmetries. Our results constitute an important development in the artificial design of large-scale films.