(ZnO)42 nanocluster: a novel visibly active magic quantum dot under first principle investigation.

A systematic density functional investigation on the structural, electronic and optical properties of the growth of (ZnO)6 cluster unit in the series of (ZnO)6n for n = 1–9 is reported in this paper. Different electronic properties of (ZnO)6n nanoclusters are analyzed in terms of HOMO–LUMO gap (HLG), ionization potential (IP), electron affinity (EA), chemical hardness (η) and electrophilicity index (ω), which all shows a zigzag behavior as the size of (ZnO)6n clusters increases. The electronic energy gain (ΔE) of the clusters identified an exceptionally stable 'magic' nanocluster, viz. (ZnO)42. Frontier orbitals analysis results indicate easy electron transfer in (ZnO)42 nanocluster system. The optical absorption spectra confirm that the magic (ZnO)42 nanocluster is active in the visible range (λ = 406.8 Å) of electromagnetic spectrum. Interestingly, like zigzag electronic properties, similar optical switching toward the growth of (ZnO)6 unit is also observed. The simulation results of electronic properties as well as the infrared spectra of magic (ZnO)42 cluster will open up a vista to the experimentalists for its possible synthesis, which in turn will help in the development of the visibly active magic (ZnO)42 nanocluster with novel applications in the fields of quantum dots or assembled materials. [ABSTRACT FROM AUTHOR]