Growth behavior and electronic and optical properties of IrGen (n=1-20) clusters

摘要

First principles calculations are performed to investigate the structural and electronic properties of small IrGen (n=1-20) clusters. Cage-like configurations where the iridium atom is encapsulated inside a germanium cage are predicted to be favored for n >= 12. Doping Ir atom enhances the stability of the corresponding germanium frame. Our results highlight the great stability of IrGe13 which presents a high-symmetry cage-like geometry and a peculiar electronic structure in which the valence electrons of Ir and Ge atoms are delocalized and exhibit a shell structure. Absorption spectra, vertical ionization potentials, and electron affinities are also calculated and discussed.