Superalkalis fabricated Te-containing [8]circulenes as outstanding NLO materials; a DFT perspective

There is a growing demand for thermodynamically stable and highly polarizable materials with excess electrons in the fields of optics. In this study, a new class of theoretically designed materials (A_xY@C₁₆Te₈ (A = K, Na, Li, and x = 2, 3 4)) are explored for optoelectronic and nonlinear (NLO) applications via DFT calculations. Various superalaklis (A_xY (Y = O, N, F and x = 2, 3, 4)) are doped on C₁₆Te₈ nano-surface. The outcomes of DFT revealed high thermodynamic stability of these complexes. Natural bond orbital (NBO) charge analysis illustrated that charge transfer occurred from superalkali toward Te-containing [8]circulene (C₁₆Te₈). HOMO − LUMO energy gap is reduced after doping. Moreover, (A_xY@C₁₆Te₈ (A = K, Na, Li, x= 2, 3 4, and Y = O, N, F) complexes exhibit remarkably large nonlinear optical (NLO) response. The static first hyperpolarizability (β_o) of these complexes ranges between 3.28 × 10³ – 2.60 × 10⁵ au. The NLO response of the designed complexes is further explored by computing second hyperpolarizability (γ_tot), frequency-dependent hyperpolarizability, and nonlinear refractive index.