Data-Driven Research for the Discovery of Novel Two-Dimensional and Ionic Materials

While two-dimensional (2D) materials are traditionally derived from bulk layered
compounds bonded by weak van der Waals (vdW) forces, the recent surprising
experimental realization of non-vdW 2D compounds obtained from non-layered
crystals [1] foreshadows a new direction in 2D systems research.
Here, several dozens of candidates of this novel materials class are presented derived
from filtering the AFLOW materials database (see Fig. 1) in conjunction with
autonomous ab initio calculations [2,3]. The oxidation state of the surface cations of
the 2D sheets is an enabling descriptor regarding the manufacturing of these systems
as it determines their exfoliation energy: small oxidation states promote easy peel off
[2]. When extending the set from oxides to sulfides and chlorides, the exfoliation
energy becomes ultra low due to strong surface relaxations [3]. The candidates exhibit
a wide range of appealing electronic, optical and magnetic properties making these
systems an attractive platform for fundamental and applied nanoscience.
[1] A. Puthirath Balan et al., Nat. Nanotechnol. 13, 602 (2018).
[2] R. Friedrich et al., Nano Lett. 22, 989 (2022).
[3] T. Barnowsky et al., Adv. El. Mats., in press (2023).