Studies on optical properties of Si220 nanoclusters via time-dependent density functional theory calculations

The optical properties of bare and hydrogen passivated Si 220 nanoclusters(NCs) in four typical motifs( i.e ., bulk-like, onion-like, bucky-diamond and icosahedral motifs) were studied via time-dependent density functional theory(TD-DFT) calculations. The calculation results show that there is a significant blue shift in the optical absorption spectra when the Si NCs are passivated with hydrogen. A strong absorption peak in the visible light region appears for the hydrogenated bulk-like, onion-like and bucky-diamond Si NCs.