Tunable Optical Properties of Icosahedral, Dodecahedral and Tetrahedral Clusters
Rui-Hua Xie, Garnett W. Bryant, J Zhao, T Kar, V H. Smith
Using time-dependent density functional theory, we show that the first singlet excitations of a series of icosahedral, dodecahedral and tetrahedral clusters are optically forbidden and that their optical absorption gaps and spectral properties are size-, shape-, composition-dependent and can be tuned broadly in the ultraviolet-visibleregion. Taking icosahedral clusters Al@Al_12} and Al@Pb_12} as examples, we demonstrate that the optical gaps of icosahedral clusters can be tailored from the ultraviolet to near-infrared by properly doping them with (transition) metals, hydrogen, group VIIB atoms, and organic functional groups. Our study suggests icosahedral, dodecahedral and tetrahedral clusters for tunable optical applications.