MA2Z4 family heterostructures: Promises and prospects

Abstract

Recent experimental synthesis of ambient-stable MoSi 2 N 4 monolayer has garnered enormous research interest. The intercalation morphology of MoSi 2 N 4 —composed of a transition metal nitride (Mo-N) inner sub-monolayer sandwiched by two silicon nitride (Si-N) outer sub-monolayers—has motivated the computational discovery of an expansive family of synthetic MA 2 Z 4 monolayers with no bulk (3D) material counterpart (where M = transition metals or alkaline earth metals; A = Si, Ge; and N = N, P, As). MA 2 Z 4 monolayers exhibit interesting electronic, magnetic, optical, spintronic, valleytronic, and topological properties, making them a compelling material platform for next-generation device technologies. Furthermore, heterostructure engineering enormously expands the opportunities of MA 2 Z 4 . In this review, we summarize the recent rapid progress in the computational design of MA 2 Z 4 -based heterostructures based on first-principle density functional theory (DFT) simulations—a central work horse widely used to understand the physics, chemistry, and general design rules for specific targeted functions. We systematically classify the MA 2 Z 4 -based heterostructures based on their contact types, and review their physical properties, with a focus on their performances in electronics, optoelectronics, and energy conversion applications. We review the performance and promises of MA 2 Z 4 -based heterostructures for device applications that include electrical contacts, transistors, spintronic devices, photodetectors, solar cells, and photocatalytic water splitting. We present several prospects for the computational design of MA 2 Z 4 -based heterostructures, which hold the potential to guide the next phase of exploration, moving beyond the initial “gold rush” of MA 2 Z 4 research. This review unveils the vast device application potential of MA 2 Z 4 -based heterostructures and paves a roadmap for the future development of MA 2 Z 4 -based functional heterostructures and devices.