Abstract
Nonlinear optical (NLO) materials have attracted bounteous scientific attention in the modern era because of their optoelectronic and biological applications. In this respect, an attempt is made to present thermodynamically stable superalkali metals (Li3N, Li3O, Li3S and Li3F)-doped sumanene (C21H12)-based complexes with fine NLO response properties. Nine isomers (I-III of Li3N@Sumanene, I-II of Li3O@Sumanene, I-II of Li3S@Sumanene and I-II of Li3F@Sumanene) are proposed, and their geometric, thermodynamic, electronic and NLO properties are explored by using density functional theory (DFT) calculations. Computational results reveal that the EH-L gap is reduced up to 0.56eV for doped complexes. The maximum hyperpolarizability response is calculated 1.084x105a.u. for isomer II of the Li3F@Sumanene series. The participation of distinct fragments, type of interaction, and charge transfer are computed by the corresponding TDOS and PDOS, NCI and NBO analysis. For UV-Vis analysis and crucial excitation state, TD-DFT calculations are carried out, which exhibits that all doped complexes are transparent in the UV region. NCI analysis confirmed the Van-der Waals interactions as an important mode of adsorption between superalkalis and sumanene. This report provides an efficient superalkali doping technique for creating highly effective future NLO systems and recommends superalkali-doped sumanene systems as ideal NLO prospects for future NLO applications.