A DFT study of structural, electronic, vibrational and optical properties of InxSby (x + y = 2–5) nanocluster

Abstract

Within Density functional theory (DFT) using B3LYP/LanL2DZ method structural, electronic and vibrational properties of InxSby (x + y = 2–5) nanoclusters have been investigated. Eighty four different geometrical structures viz linear, planer and three dimensional have been optimized and bond lengths, binding energy (BE), and HOMO-LUMO gaps are calculated for all the optimized clusters. Structures which have highest binding energy (BE) for a specific chemical composition are considered as most stable. For the most stable clusters vibrational frequencies, IR intensities, Raman activity, Ionisation potential (IP), Electron Affinity (EA) and optical spectra are determined. The binding energy of the most stable clusters increases monotonically with the size of the cluster. TDDFT-B3LYP/LanL2DZ formalism has been used to study the optical properties. The optical absorption spectra are determined for the most stable nanoclusters. It has been seen that absorption spectra is quite feeble in the visible range and most prominent strong peaks are appeared in Ultraviolet (UV) region and in case of five atom Indium antimonide clusters it is totally opposite i.e. strong peaks are observed in visible range and less prominent peaks are observed in UV region. It may be utilized as a promising material for the devices which works in the UV region as well as in visible region.