Layered functional materials - beyond 'graphene'

Objective

There is an apparent lack of non-metallic 2D-matrials for the construction of electronic devices, as only five materials of the “graphene family” are known: graphene, hBN, BCN, fluorographene, and graphene oxide – none of them with a narrow bandgap close to commercially used silicon. This ERC-StG proposal, BEGMAT, outlines a strategy for design, synthesis, and application of layered, functional materials that will go beyond this exclusive club. These materials “beyond graphene” (BEG) will have to meet – like graphene – the following criteria:
(1) The BEG-materials will feature a transfer of crystalline order from the molecular (pm-range) to the macroscopic level (cm-range),
(2) individual, free-standing layers of BEG-materials can be addressed by mechanical or chemical exfoliation, and
(3) assemblies of different BEG-materials will be stacked as van der Waals heterostructures with unique properties.
In contrast to the existing “graphene family”,
(4) BEG-materials will be constructed in a controlled way by covalent organic chemistry in a bottom-up approach from abundant precursors free of metals and critical raw materials (CRMs).
Moreover – and unlike – many covalent organic frameworks (COFs),
(5) BEG-materials will be fully aromatic, donor-acceptor systems to ensure that electronic properties can be addressed on macroscopic scale.
The potential to make 2D materials “beyond graphene” is a great challenge to chemical bond formation and material design. In 2014 the applicant has demonstrated the feasibility of the concept to expand the “graphene family” with triazine-based graphitic carbon, a compound highlighted as an “emerging competitor for the miracle material” graphene. Now, the PI has the opportunity to build a full-scale research program on layered functional materials that offers unique insights into controlled, covalent linking-chemistry, and that addresses practicalities in device manufacture, and structure-properties relationships.