Designing hybrid zinc-based ultraviolet nonlinear optical crystal with strong NLO response and dual-color luminescence via the integration of two different SHG-active genes

Planar π-conjugated units, d 10 electronic configuration metal ions and tetrahedral groups are effective SHG-active groups to construct excellent nonlinear optical (NLO) crystals. Herein, a novel organic-inorganic hybrid noncentrosymmetric (NCS) (C 8 H 14 N 2 )ZnBr 4 crystal was rationally designed and synthesized via combing planar π-conjugated 4-ethanaminomethylpyridine and d 10 metallic [ZnBr 4 ] 2- tetrahedron. Notably, it features an excellent balanced NLO properties, including a strong second harmonic generation (SHG) response (2.9 × KDP), suitable birefringence (0.057 at 546 nm), a short cut-off wavelength (261 nm), high thermal stability (268 °C) and a high laser-induced-damage-threshold (LIDT) of 8.15 MW cm −2 . Interestingly, an excitation-induced tunable blue and yellow dual-color luminescence was also observed for (C 8 H 14 N 2 )ZnBr 4 , which can be attributed to organic component and self-trapped exciton, respectively. First-principles calculations were carried out to explore structure-property relationship, which revealed that optical properties of (C 8 H 14 N 2 )ZnBr 4 are synergistic contributed by the distorted [ZnBr 4 ] 2- tetrahedron and planar π-conjugated organic (C 8 H 14 N 2 ) 2+ cations. This work not only provides an excellent NLO crystals, but also offers an effective strategy to design novel hybrid NLO materials with favourable optical performances. Through synergistic assembly of π-conjugated (C 8 H 14 N 2 ) 2+ and d 10 -metallic [ZnBr 4 ] 2- tetrahedral genes, mutifunctional (C 8 H 14 N 2 )ZnBr 4 crystal with outstanding NLO properties (a strong SHG response of 2.9 × KDP@1064 nm, a short UV cut-off edge of 261 nm, suitable birefringence 0.057 @ 546 nm, and a high thermal stability up to 268 °C) and dual-color luminescence was synthesized. • Bulky crystal (C 8 H 14 N 2 )ZnBr 4 with high stability up to 268 °C was synthesized. • High SHG efficiency, short cutoff edge and moderate birefringence were obtained. • An blue and yellow dual-color luminescence was also observed for (C 8 H 14 N 2 )ZnBr 4 . • Theoretical calculation was conducted to study the relation of structure-property.