Lead Mixed Oxyhalides Satisfying All Fundamental Requirements for High‐Performance Mid‐Infrared Nonlinear Optical Materials
Xinglong Chen, Hongil Jo, Kang Min Ok
Abstract
Abstract To design high‐performance mid‐infrared (mid‐IR) nonlinear optical (NLO) materials, we have focused on the combination of a heavy metal lone pair cation, Pb 2+ and mixed oxyhalides. A systematic investigation in PbO‐PbCl 2 ‐PbBr 2 system led us to discover the first examples of NLO lead mixed oxyhalides, namely, Pb 13 O 6 Cl 4 Br 10 , Pb 13 O 6 Cl 7 Br 7 , and Pb 13 O 6 Cl 9 Br 5 . All the reported materials have remarkably comprehensive properties including broad IR transparency (up to 14.0 μm), qualified second harmonic generation (SHG) responses (0.6–0.9×AgGaS 2 ), wide band gaps (3.05–3.21 eV), and ease of crystal growth. Interestingly, a centimeter‐sized single crystal (2.9×1.3×0.5 cm 3 ) of Pb 13 O 6 Cl 9 Br 5 revealing a wide transparent range (0.384–14.0 μm) and high laser damage threshold (LDT) (14.6×AgGaS 2 ) has been successfully grown in an open system. The study suggests that all the reported mixed oxyhalides are outstanding candidates for mid‐IR NLO materials.