Data-Driven Design of Two-Dimensional Non-van der Waals Materials

• Applicant: Dr. Rico Friedrich
• Subject Area: Theoretical Chemistry: Molecules, Materials, Surfaces
• Term: since 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 513655797

Two-dimensional (2D) materials have attracted extensive research interest due to the unique topological, magnetic and catalytic features they exhibit. These compounds are traditionally associated with the sheets forming bulk layered crystals bonded by weak van der Waals (vdW) interactions as exemplified by the most prominent example of graphene derived from bulk graphite. The recent surprising synthesis of atomically thin 2D sheets from non-vdW bonded oxides opens up a new perspective for this diverse class of nanostructures. Non-vdW 2D materials are an emerging class of nanoscale compounds exhibiting novel properties and functionality. This project aims to identify all bulk materials capable of forming non-vdW 2D materials and to thoroughly characterize and functionalize them. For this purpose, data-driven methodologies — an approach still underrepresented in Germany compared to the United States — are the ideal tool. The project will make use of the AFLOW database – one of the largest materials repositories to date including over 3.5 million systems characterized by over 700 million properties. First, accurate exfoliation energies, i. e. the energies needed to cleave the 2D sheets from the bulk surface will be obtained from the coordination corrected enthalpies method developed by the applicant. Based on the corrected energetics, the ab initio surface functionalization of the candidates can be realized. The adsorption of molecular species as well as the encapsulation between graphene sheets provide a comprehensive means to tune the properties of the candidates – valuable input for the experimental collaborators at Rice University. To identify all possible candidates in the AFLOW database capable of forming 2D non-vdW systems, a rigorous filter criterion, i. e. descriptor, is needed. By generalizing previously identified structural and electrostatic patterns promoting the formation of 2D sheets, a universal descriptor will be developed and, in collaboration with the partners from Duke University, implemented into AFLOW to be applied to the associated database. The obtained new candidates – presumably several thousand – as well as suitable heterostructures will then be characterized thoroughly according to their electronic, optical and magnetic properties. The most appealing systems will be suggested to the experimental collaborators at Rice University for synthesize. Thus, the proposed project will help to reveal the potential of the novel class of non-vdW 2D materials by leveraging data-driven research principles.

• DFG Programme: Research Grants
• International Connection: USA
• Cooperation Partners: Professor Dr. Pulickel Ajayan; Professor Dr. Stefano Curtarolo