Quantifying plasmonic characteristics of a series of pure Aluminum and alkali doped Aluminum clusters

Abstract Al clusters have drawn tremendous attention of scientific community for their characteristic deep ultraviolet plasmonic emission. In this study, we have explored the plasmonic characteristics of a series of linear (Aln; n = 2 to 9) and cyclic aluminum clusters (n = 3,4) along with our recently reported three Al13+ isomer system [Guin et. al. Journal of Molecular Graphics and Modeling, 2020, 97, 107544] and corresponding alkali doped clusters [Guin et. al. Journal of Molecular Modeling, 2021, 27, 235]. Among the three Al13+ isomers one is perfectly planar (CI) and two others are quasi-planar clusters (CT and CII). It is a well-known fact that properties of nano-clusters strongly depend on the size and shape of the clusters. The current study reveals that for the linear chains the plamonic character systematically increases with the nuclearity of the clusters. For the cyclic clusters (Al3 and Al4) the plamonicity is lower compared to corresponding linear clusters. In case of Al13+ isomer system, the planar isomer is having higher plasmonicity compared to the non-planar isomers. The doping of alkali atoms in planar clusters, has a general tendency to reduce the plasmonic nature compared to the undoped clusters. The plasmonic emission for these aluminum clusters fall in the UV range (170 to 416 nm).