Change in nonlinear optical response of C24 nanocage upon doping with lithium based superalkalis

Abstract

Density functional theory (DFT) calculations are used to analyze the change in nonlinear optical (NLO) response, electronic and geometric properties of the Li based superalkalis doped C24 nanocage. It was observed that the adsorption of Li4N, Li3O and Li2F superalkalis on C24 nanocage results in thermodynamically stable isomers (A-F). The energy gap between the highest occupied and the lowest unoccupied molecular orbitals (GH-L) is reduced after superalkalis doping on carbon (C24) nanocage. Density of states spectra depict the strong contribution of superalkalis in HOMOs of the considered complexes. Natural bond orbital (NBO) charge analysis showed that the charge is being transferred from superalkali toward C24 nanocage. The values of polarizability (α o ) and hyperpolarizability (β o ) showed that doping of superalkalis on C24 has a significant effect on its NLO response, resulting in a considerable increase in values of α o and β o . Li4N@C24 isomer E showed the highest β o value of 6470.74 au. Time dependent density functional theory (TD-DFT) calculations are implemented to analyze the absorption spectra. This research provides unique and highly efficient superalkalis doped C24 isomers for their applications in future electronic devices.