Computational study of Be, Mg and Ca decorated Si₁₂B₁₂ nanocages with proficient nonlinear optical properties

Abstract

Scientists have paid much attention to nanoscale nonlinear optical (NLO) materials in recent decades due to their promising applications in telecommunications, electronics, and optics. Here, we endeavored to design alkaline earth metals (Be, Mg, and Ca) doped Si12B12 nanocage to meet the rapidly widening requirement for NLO materials. Density functional theory (DFT) and time-dependent DFT (TDDFT) assisted computational tools are utilized to explore the impact of alkaline earth metals doping on the NLO response of Si12B12 nanocage to reveal a unique method for developing NLO materials. Theoretically, ten new isomers of alkaline earth metals doped Si12B12 nanocages are designed. The computational findings demonstrated that the doped isomers of Si12B12 nanocage have significant thermodynamic stabilities, with the highest binding energy of -74.15 kcal mol-1. The EH-L gap is excellently declined upon Be, Mg, and Ca doping and the lowermost EH-L gap is found at 0.92 eV. Calculations using TD-DFT revealed that isomers of the Si12B12 nanocage are transparent in the ultraviolet (UV) region. Confirmation of charge transfer and participation of different segments is explored by natural bond orbital (NBO) and total density of state (TDOS) as well as partial density of state (PDOS) analysis respectively. The types of interactions are investigated using non-covalent interaction (NCI) analysis. The isomer SiB-XV of Ca doped Si12B12 nanocage exhibits the eye-catching static first hyperpolarizability value of 4.71×104 au. Overall findings conclusively confirm that alkaline earth metals doped isomers of Si12B12 nanocage are potential contenders for nanoscale NLO materials because they have excellent stability and boosted NLO response. This research will cover the approach for the fabricating of large NLO response materials for innovative NLO applications.