Achiral Fluorinated Aromatic Ligands Based Chiral Hybrid Antimony Halides with High‐Efficiency Second‐Harmonic Generation.

Hybrid organic−inorganic metal halides (HOMHs) have emerged as an ideal platform for the construction of semiconductor materials with promising optoelectronic properties. A number of HOMHs based on different metals including Sb3+ have been demonstrated with second‐harmonic generation (SHG) properties, but their nonlinear optical (NLO) performances including effective conversion wavelength range, optical stability, and NLO coefficients are not yet satisfactory. Here, by adopting a molecular design involving fluorine‐substitution on the achiral organic ammonium, this work has synthesized single crystals of two new chiral noncentrosymmetric HOMHs, (2‐FPEA)2SbX5 (X = Cl and Br), with large polarization ratios and outstanding optical transparency. The second‐order NLO coefficients of (2‐FPEA)2SbCl5 and (2‐FPEA)2SbBr5 are determined to be ≈24.3 and 21.6 pm V−1. Significantly, the Sb3+‐based HOMHs enable very high thermal stability and laser resistance. The distinguished laser‐induced damage thresholds (LDTs) have been estimated to be as high as 3.44 mJ cm−2 for (2‐FPEA)2SbCl5 and 3.32 mJ cm−2 for (2‐FPEA)2SbBr5, higher than that of the reported HOMHs. Such a highly efficient SHG performance and stability indicate the promising future of these Sb3+‐based metal halides for nonlinear photonic applications. [ABSTRACT FROM AUTHOR]