New nanomaterials based on In12As12cages: an ab initio bottom-up study

Abstract

We report the results of density functional calculations on nanostructures of InAs, including the small InnAsn (n = 1–15) clusters, the stable hollow cage In12As12 and its derivative nanomaterials (In12As12-based dimer, trimer, nanowire, sheet, and new nanoporous crystal phase). Our results show that among the small InnAsn (n = 1–15) clusters, the In12As12 cage structure with Th symmetry and large HOMO–LUMO gap is proved to be the most stable one, indicating that it would be an ideal building block for the synthesis of cluster-assembled materials. Via the coalescence of In12As12 building blocks, we find that the In12As12 cages can bind into various nanomaterials with different dimensionality by the most stable bonding via In6As6 hexagonal faces forming intercluster hexagonal prism. All of these constructed nanostructures are found to be more stable than the individual In12As12 cage and rock salt (RS) phase of InAs. The band analysis reveals that the periodic In12As12-assembled nanomaterials have relative band gap magnitudes of 2.00–4.89 (Eg/Eg,ZB) with respect to the zinc blende (ZB) phase of InAs, and the new nanoporous polymorph holds an indirect gap of ∼0.86 eV, which may extend the range of properties and applications of the InAs compound.