Lizardite–h-BN heterostructures—Application of clay minerals in technology

Abstract

Graphene has been a subject of great interest not only due to its fascinating properties but also for being the pioneer among 2D van der Waals (vdW) materials. Hexagonal boron nitride, an isomorph of graphene and a wide gap insulator, is commonly referred to as white graphene. The combination of the insulating hexagonal boron nitride (h-BN) with other crystals to form heterostructures provide a path for engineering and manipulating new physics and device properties. In this work, we investigate the vdW heterostructures formed by assembling h-BN and lizardite, a clay-mineral that is abundant in nature and represents the most stable polymorph of the serpentine family. The optoelectronic properties of three distinct heterostructures are presented to discern the characteristics of the systems. We observe that unlike lizardite and h-BN which are insulators, all the three heterostructures exhibit a semiconducting nature. The direct gap of the heterostructure in which two h-BN sheets are simultaneously placed above and below the octahedral and tetrahedral layers also makes it relevant for optoelectronic devices. Additionally, unlike lizardite, the heterostructures demonstrate a polarization-dependent optical properties. The study of the assembled structures combining the clay-mineral with h-BN not only widens the spectrum of vdW heterostructures but also explores their potential within the context of the serpentine family.