Introduction to the Class of 2D Materials with a focus to hBN
Dr Annick Loiseau
LEM, ONERA-CNRS, U. Paris Saclay, Châtillon, France
The talk will be first an introduction to graphene and the family of 2D crystals with a discussion of the promises and challenges for this new class of materials. Today potentially thousands of materials are identified to exhibit singular and new properties with respect to their bulky counterparts, which range from metal and semimetals to semiconductors, insulators, supraconductors and charge density waves. This opens a new horizon to build up new composite materials, new devices and new device concepts where the key is multifunctionnality achievable by the manufacturing of multicomponent heterostructures. To this end, the controlled, ultraclean and large scale stacking up of 2d materials remains a materials science challenge. Therefore synthesis processes, which implies the development of a crystal growth technology for addressing device integration as well as characterization methods have to be defined and worked out for the 2D materials, gradually as their potential emerges.
The talk will then focus to a singular 2D crystal, hexagonal boron nitride (h-BN) material and its today strategic interest as a layered 2D material. H-BN is a wide band gap semiconductor (~ 6.5 eV), sp2 hybridized and isoelectronic to graphite, which has been proved to be a key material for building heterostructure and devices as it can be used as insulating substrate, capping protective material or dielectric layer.Nevertheless, all these capabilities have been demonstrated using mechanically exfoliated layers from single crystals, highlighting the urgency to get of alternative sources of BN layers from scalable synthesis routes. The talk will review the recent effort focused on the development of reliable synthesis techniques as well as the effort for the development of reliable characterization methods based on the knowledge and understanding of peculiar spectroscopic properties.