Computational analysis of [AunSi]+ (n = 1–5) nanoalloy clusters

Abstract

Study of silicon doped gold nanoalloy cluster is of great importance due to its prospective applications in optoelectronic and photovoltaic cells. In this article, computational investigation of cationic state for silicon doped gold nanoalloy cluster [Au n Si] + (n = 1–5) is carried out with the help of Density Functional Theory (DFT) methodology. For optimization and modeling of clusters functional B3PW91/LANL2DZ is selected. Density functional theory based global descriptors along with dipole moment and symmetry configuration of [Au n Si] + are computed. The computed data illustrates that energy difference between HOMO and LUMO energy gap varies from 2.149 to 3.549 eV. Maximum stability is found for cluster [Au 3 Si] + with symmetry configuration D 3h whereas cluster [Au 4 Si] + with symmetry group C 2V shows the least stability. The HOMO-LUMO energy gap of [Au n Si] + nanoalloy clusters exhibits direct correlation with molecular hardness. An odd–even swinging behavior is noted among energy gap and number of gold atoms, indicating that cluster with odd number of gold atoms shows HOMO-LUMO gap higher in comparison with their contiguous system with even number of gold atoms.