Cs<sub>3</sub>Pb<sub>2</sub>(CH<sub>3</sub>COO)<sub>2</sub>X<sub>5</sub> (X=I, Br): Halides with Strong Second‐Harmonic Generation Response Induced by Acetate Groups
Qirui Shui, Hong‐Xin Tang, Ruibiao Fu, Yuan‐Bin Fang, Zuju Ma, Xintao Wu
Abstract
Abstract Nonlinear optical (NLO) crystals are the key component in solid‐state lasers. New second‐harmonic generation (SHG) effective halides, Cs 3 Pb 2 (CH 3 COO) 2 X 5 (X=I, Br), have been rationally synthesized by introducing acetate groups into lead halide perovskites under moderate solvothermal conditions. Cs 3 Pb 2 (CH 3 COO) 2 X 5 (X=I, Br) feature highly oriented anionic chains constructed by distorted [PbX 4 O 2 ] (X=I, Br) polyhedrons. Both the theoretical studies and the dipole moment calculations uncover that their SHG effects are mainly originated from the distorted [PbX 4 O 2 ] (X=I, Br) polyhedrons. Remarkably, Cs 3 Pb 2 (CH 3 COO) 2 I 5 exhibits strong phase‐matching SHG response (8×KDP) and large birefringence (0.26@ 1064 nm). Moreover, Cs 3 Pb 2 (CH 3 COO) 2 X 5 (X=I, Br) also possess high laser damage threshold (LDT) which are almost 27 and 41 times that of AgGaS 2 , respectively.