Exploring 2D structures of indium oxide of different stoichiometry

The emergence of specific and outstanding 2D-structure-related material performance has motivated a search for 2D atomic structures that can even be described as non-van-der-Waals-type materials. This has been exemplified with materials from group IV and group III–V which naturally crystallize in diamond, zincblende or wurtzite crystal structures. Here, we give insight into various atomic structures of indium oxide at the 2D limit featuring different stoichiometry, including 2D InO and 2D In2O3. We find that 2D InO with an InSe-type structure and its characteristic In–In distances compare closely with available first-time experimental results. An as yet unexplored 2D structure of indium oxide is found to be a planar hexagonal monolayer of h-In2O3.