Exploring the nonlinear optical characteristics of supersalt-decorated graphyne via DFT analysis: unveiling quantum insights into light-matter interaction

Abstract In this comprehensive study, we explore into the nonlinear optical (NLO) properties of graphyne (GRY) and its compounds decorated with a super salt (OLi3BeF3), namely GRY@SS1, and GRY@SS2) using the rB 3 LYP / 6 − 31 G ( d , p ) DFT method. Our findings reveal a substantial enhancement in the electron transfer properties of decorated compounds compared to the pristine GRY surface. This enhancement is evidence by the reduction in the bandgap energies ( E g ) from 3.52 eV to 1.68 eV and remarkable boost in maximum absorption ( λ max ) from 372.66 to 807.73 nm. Noteably, GRY@SS2 exhibits a significant increase in linear polarizability ( α 0 ) (538.18 au), first hyperpolarizability ( β 0 ) (3872.76 au), and second hyperpolarizability ( γ 0 ) (1.00 × 106) due to reduced excitations energies compared to the GRY ( α 0 = 448.61, β 0  = 0.14 and γ 0  = 5.97 × 105 au). NBO charges show that electrons are transferring from the dopant (supersalt) to the GRY sheet. Furthermore, Non-covalent interactions (NCl), iso-surface, infrared (IR), 1H NMR, and 13C NMR studies have been conducted to provide insights into the nature of interactions, vibrational frequencies, and structural-functional aspects of GRY and GRY@SS1, and GRY@SS2. According to TD-DFT calculations, all compounds demonstrate superior vertical ionization potential, UV–vis absorbance, HOMO–LUMO characteristics, as well as interaction energies. Our results underscore the potential of these compounds as valuable NLO materials, particularly highlighting the promising prospects of GRY@SS2.